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Copyright John Dunn Engineering

Welcome to the Barclay Blog.

No.8 was the last 16″ 0-4-0 saddle tank built by the Kilmarnock firm of Andrew Barclay and Sons Ltd. Works No. 2369 she was delivered new to the Scottish Region of the National Coal Board in 1955, the last brand new steam locomotive they bought.

I am lucky enough to own a 3/4 share in the locomotive and I thought people might be interested to follow the overhaul, maintenance, and day to day running of a full sized industrial “pug”.

If you are new to the site and would like to receive notifications whenever fresh posts appear please contact me through the “Replies” tab above; introduce yourself and remember to tick the relevant box!

Please feel free to contribute. I am keen to hear the experiences of anyone else who is, or has been, involved with Barclays, whether in industry or in preservation. Any relevant steam or engineering experience would be welcome, as would any constructive criticism. Photographs or information about No.8 when she was in service would be extremely useful.

Please have a good browse around and I hope you find the site interesting.

John.

Reflections and Thoughts.

The last post was quite lengthy and took some time to write. We have now got settled in at Scunthorpe and work is progressing rapidly. It is amazing what a difference a heated shed, pits, good lighting and a society that is definitely steam orientated makes! It really has been a breath of fresh air.

I will post some updates of the work we are currently on with soon but I thought it might be appropriate to share a few thoughts about the overhaul so far. Inevitably there are some things I would do differently and I thought it might help others to avoid the same pitfalls.

  1. Shed. If we were starting again I would move the locomotive to some sort of covered accomodation at the outset. I estimate the battle with the elements has cost us between 2-1/2 and 3 years of lost time. Work outside between the end of November and the end of March is very difficult if not impossible. Security is an issue; everything has to be moved to a container when it has been removed from the locomotive – and then retrieved next time. Tools have to be locked away. The sheet has to be removed and then put back on. You lose a couple of hours a day just preparing and packing up, and when the daylight hours are short it leaves little time for productive work. Added to that of course is the weather, lighting, an electricity supply, compressed air, lack of solid floors; the list goes on and on. There is nothing romantic about it, even through rose-tinted glasses; it’s a nightmare scenario and not for the faint hearted! I take my hat off to the lads involved with No.8 because they stuck at it through everything.

    Settled inside the shed and ready for work to commence. (Copyright Jonathan D. Stockwell).

    Settled inside the shed and ready for work to commence. (Copyright Jonathan D. Stockwell).

  2. Frames. It sounds slightly ridiculous now, but I made the somewhat naive error of assuming the frames would be straight and square; they aren’t. This mistake resulted in a lot of wasted time because of the need to repeat measurements and calculations. Check the truth of the frames before you do anything else.

    Reference Marks (copyright John Dunn Engineering)

    Reference Marks (copyright John Dunn Engineering)

  3. Measurements. I have detailed the method we used for obtaining the various measurements as well as how we set the axle centres out. It was only after we had finished the work on the horns that I was talking to Ron Hill. Ron served his apprenticeship at Cowlairs Works and was good enough to send me the details of how it was done there; the LNER system was simpler and less open to error than the method we used. If I had to undertake the job again I would seriously consider using the Cowlairs system to set out the position of the axle centres relative to the cylinders. The position of the axleboxes relative to the centre-line of the locomotive was more complicated than normal owing to the bend in the frames. Martyn Ashworth was good enough to supply me with a copy of how this was achieved on the LMS and, if the frames had been straight, I would have used this method; it was simple and I know it works. Unfortunately, under the circumstances we were presented with, it would not have worked and we had to ascertain the measurements by more complicated means.

    Tramming the back axle datum rod by touching the pointer to the wire on the left. (Copyright John Dunn Engineering).

    Tramming the back axle datum rod by touching the pointer to the wire on the left. (Copyright John Dunn Engineering).

  4. Drawings. When we started the overhaul we had no drawings so we were “flying blind”. This is not the end of the world, but it does make things simpler if you can see what things should have looked like originally. It is not always clear what original sizes should have been, or whether something that has been done was a repair or had been intended that way by the designer. The Barclay Archive at Glasgow University is the repository for the surviving Barclay drawings. The staff there are extremely helpful but the on-line catalogue system is not particularly comprehensive or informative. It took two visits to the Archive before I found the drawings we needed, and we were well into the overhaul by the time this information came to light. The drawings made things a lot easier, had they been available at an earlier stage I would possibly have approached some of the work differently. With experience, I would spend more time obtaining drawings at the beginning, I don’t think the effort would be wasted.

    One of the brasses with both oilways drilled. The drawing in the background was done quickly to give me the angles needed for drilling the oilways but it shows how the design was modified so that the oilway enters the oilgroove from the top rather than the side. (Copyright John Dunn Engineering).

    One of the brasses with both oilways drilled. The drawing in the background was done quickly to give me the angles needed for drilling the oilways but it shows how the design was modified so that the oilway enters the oilgroove from the top rather than the side. (Copyright John Dunn Engineering).

  5. Thrust-Faces. The drawings made a massive difference to the way we approached this bit of the job. Had they been available earlier I would have been inclined to standardise the diameter and position of the faces. As it was, I took out the minimum amount of metal from each “pocket” to ensure the wear was removed. We’ve lost nothing but I prefer the idea of everything being standard.I have mentioned before, I think, that I had initially been under the impression that the outside faces of the keeps formed part of the thrust face. Once again, the axlebox drawing showed the error of my assumption but, by the time this came to light, we had already paid for a pattern and some castings to make-good the keeps. I would repair the wear on the outer faces of the keeps by another means next time.

    The left leading axlebox after completion of the work described here. (Copyright John Dunn Engineering).

    The left leading axlebox after completion of the work described here. (Copyright John Dunn Engineering).

  6. Horn Cheeks. These were already drilled and tapped for new faces, the work having being undertaken by the NCB, so our hands were tied in this respect; the replacement faces had to be fixed to the existing horns – as opposed to fitting them to the axleboxes which would, I think, have been my preferred method. The new cheeks were made from bright mild steel, they could equally have been made from gauge plate or phosphor bronze; the main thing was to achieve a material differential with the axlebox. The new faces were positioned with shims, the aim being to achieve the correct position and clearance for the axlebox. This did not go as planned; I anticipated that it would be a relatively simple job but, in reality, the need to use shims of various thicknesses in different areas of the horn-face gave rise to all sorts of issues with distortion. I ended up having to grind the faces flat to a surface plate, as detailed in the relevant post, which was time consuming and laborious work; next time I would dispense with the shims altogether. I would mill or grind the new faces to approximate thickness, screw them on and then grind them back to a surface plate. This method would, I think, be quicker and less prone to problems with distortion.

    Still a bit to go yet but you can see the blue gradually covering even more of the face. The closer we get to finishing, the thinner the coating of blue applied to the surface plate which makes for more accuracy. (Copyright John Dunn Engineering).

    Still a bit to go yet but you can see the blue gradually covering even more of the face. The closer we get to finishing, the thinner the coating of blue applied to the surface plate which makes for more accuracy. (Copyright John Dunn Engineering).

  7. Axlebox Crowns. The bearing brasses took an age to fit to the axlebox crowns. I think this was due to wear in the crowns which had made the radii go out of true; this was probably caused by the original brasses “fretting” when in service. The problem was that, due to the design of the axlebox, it was very difficult to measure this wear. Next time I would spend more time trying to establish the truth of the radii and the surfaces within the crowns. If I had any doubts, I would be inclined to take a very light skim through the crown to true everything up. Time spent here would be more than repaid in a reduction in fitting time.

Re-Wheeling.

Inevitably, I wasn’t too sure just how well the re-wheeling process would go. In theory everything should have fitted together perfectly but of course, in practice, there are so many variables that things don’t always go as planned. In an effort to give ourselves as much time as possible, Paul and I took the week of the August Bank Holiday off work; Mike took the Tuesday off and kept both weekends free; Stuart and Jonathan made themselves available for both weekends and the Bank Holiday Monday. In theory we had plenty of man-hours at our disposal, now we just needed the gods to smile on us and deliver a week of decent weather; a fairly major request bearing in mind the poor showing throughout the summer!

Left to right: Jonathan, me, Stuart and Paul. This was taken just before we set off to transport everything to Murton. Mike was already on-site. (Copyright John Dunn Engineering).

Left to right: Jonathan, me, Stuart and Paul. This was taken just before we set off to transport everything to Murton. Mike was already on-site. (Copyright John Dunn Engineering).

My plan had been to approach the job in stages with a set of achievable goals for each day, but with a degree of flexibility built-in for any unforseen eventualities. If things went well and the axleboxes fitted in the horns without any problems we would aim to get the brake rigging back on, and get the locomotive mobile, by the end of the week. If problems were encountered with the fit of the ‘boxes then the week would be spent resolving these; in this case, where we ended up at the 2nd weekend would depend on the scale of the problems encountered. Of course, added into this mix was the weather!

SATURDAY: all of the tools, equipment and the axleboxes were transported to Murton. Apart from the more obvious hand tools we needed jacks, steel sheets (because of the ash ballast), a barrow with a hydraulic lifting table, strops, rope; the list went on and on – and most of it is fairly heavy, bulky and difficult to handle. By knocking off time we had unloaded everything at Murton and got it all under lock and key in a secure container; exactly where I had wanted to be by this stage.

Saturday evening and the axleboxes are inside the container at Murton. You can also see some of the brake rigging and the brake blocks. (Copyright John Dunn Engineering).

Saturday evening and the axleboxes are inside the container at Murton. You can also see some of the brake rigging and the brake blocks. (Copyright John Dunn Engineering).

One of the axleboxes being tried in position using the hydraulic table on the barrow. (Copyright John Dunn Engineering).

One of the axleboxes being tried in position using the hydraulic table on the barrow. (Copyright John Dunn Engineering).

 

SUNDAY: the horns were degreased and cleaned and the axleboxes were then tried in place to check that they fitted correctly. Each ‘box was placed on the hydraulic barrow which was manoeuvred to place the ‘box correctly into position, the table was then raised to slide the axlebox into the horns. This sounds simple but, once again, the ash made things difficult; we placed steel sheets down to make a smooth surface and to prevent the barrow’s wheels from sinking under the weight.

 

 

By way of a comparison to the previous photograph, here the barrow has been lowered slightly and the 'box is "hanging-up" as explained in the text. (Copyright John Dunn Engineering).

By way of a comparison to the previous photograph, here the barrow has been lowered slightly and the ‘box is “hanging-up” as explained in the text. (Copyright John Dunn Engineering).

 

I was extremely relieved to find that all four ‘boxes slid smoothly into place without any adjustments being required and the fit appeared to be spot-on. I am told that conventional axleboxes such as these should “hang-up” in the horns if the fit is correct, in other words they should not slide out under their own weight until given a very slight nudge with a short crowbar, and I was pleased that this had been achieved. All the measuring and time spent machining and fitting was paying off – so far anyway. The aim now was to get the locomotive back onto her wheelsets; as a precursor to tomorrow’s efforts the new oiler pads were put into oil to soak overnight.

 

Two of the oiler pads just prior to being put into oil to soak. (Copyright John Dunn Engineering).

Two of the oiler pads just prior to being put into oil to soak. (Copyright John Dunn Engineering).

BANK HOLIDAY MONDAY: once again, all of the tools, equipment and the axleboxes were moved the 150 yards from the container to No.8’s siding; no easy job – ash ballast again. The journals and thrust faces on the rear of the wheels were degreased and given a polish with fine emery tape, we were then ready for the actual re-wheeling operation.

The usual procedure for re-wheeling involves placing all of the axleboxes on the journals with the keeps in place. The locomotive is then carefully lowered down onto the fully assembled wheelsets and, if all goes according to plan, the axleboxes enter the horns smoothly and the locomotive ends up back on terra-firma. We had risk-assessed the operation and felt that, because of the conditions on-site, another method might be more practical and safer.

The keeps were removed from the axleboxes and the ‘boxes were then lifted into their respective horns; they were suspended in place using a bar across the top of the horns and some high breaking strain rope, hopefully the photograph will make this clear. Once all four axleboxes were located the locomotive was see-sawed down by alternately jacking at each end of the locomotive. On completion it only remained to replace the keeps along with the new oiler pads.

One of the axleboxes suspended in position as described in the text. (Copyright John Dunn Engineering).

One of the axleboxes suspended in position as described in the text. (Copyright John Dunn Engineering).

It all sounds simple but it was actually a very difficult job for various reasons. The ash got everywhere and we ended up having to put the journals in “dry”, i.e. without a film of oil, because the ash kept blowing into the bearing and sticking to the oil which meant everything had to be cleaned. The clearance under the loco was very restricted once she was nearly back down and this made re-fitting the keeps (along with the oiler pads) extremely long-winded and awkward.

Oiler pad and keep ready for fitting. The pad has been soaked in oil, hence the change of colour. (Copyright John Dunn Engineering).

Oiler pad and keep ready for fitting. The pad has been soaked in oil, hence the change of colour. (Copyright John Dunn Engineering).

We were eventually beaten by the light but we finished the day with all the keeps replaced and No.8 at the stage where, in the morning, she would only need dropping a few inches before the weight was on the springs again.

The situation as it was at the end of the day; the 'box is in the horns and down on the axle, the keep has been replaced. The 'G' clamp is preventing the spring pin from dropping. (Copyright John Dunn Engineering).

The situation as it was at the end of the day; the ‘box is in the horns and down on the axle, the keep has been replaced. The ‘G’ clamp is preventing the spring pin from dropping. (Copyright John Dunn Engineering).

TUESDAY: this was a fairly relaxed day after the stresses of the weekend. No.8 was jacked down until all of her weight was being taken by the springs. The horn stays were replaced and the brake rigging was cleaned. We even allowed ourselves a celebratory cup of tea!

The rest of the day was spent tidying up the site around the locomotive.

The rear right driving axlebox after completion of re-wheeling. The horn-stay has now been re-fitted. (Copyright John Dunn Engineering).

The rear right driving axlebox after completion of re-wheeling. The horn-stay has now been re-fitted. (Copyright John Dunn Engineering).

WEDNESDAY: Paul and I spent the day re-fitting the brake rigging. Although this needs some attention it was necessary to have it on the locomotive for the impending move to Scunthorpe. The job was a rather long-winded affair because of the difficulties with access and clearance underneath No.8.

The brake rigging has been replaced. This is only temporary, it will all be removed for overhaul once the locomotive has been moved to the AFRPS at Scunthorpe. (Copyright John Dunn Engineering).

The brake rigging has been replaced. This is only temporary, it will all be removed for overhaul once the locomotive has been moved to the AFRPS at Scunthorpe. (Copyright John Dunn Engineering).

THURSDAY: the locomotive was given a thorough examination in preparation for being moved out of the siding. A number of components which had been removed were replaced and secured; other parts had been loosened off during the overhaul and these were also made safe.

FRIDAY: we had a day off!

Not the best of photographs because I was fairly busy but this shows No.8 being shunted out of the siding by the DVLR's 88DS. It was fitting that one of our lads, Stuart, was driving. (Copyright John Dunn Engineering).

Not the best of photographs because I was fairly busy but this shows No.8 being shunted out of the siding by the DVLR’s 88DS. It was fitting that one of our lads, Stuart, was driving. (Copyright John Dunn Engineering).

SATURDAY: No.8 was moved out of the siding for the first time since the overhaul had been started on 2009; everything went well and she was shunted around the yard without any problems. The pistons and cylinder end-covers were all temporarily replaced in preparation for the move; it was easier to get them transported with the locomotive rather than the alternative of having to lug them there ourselves.

The cylinder end covers and pistons have all been temporarily replaced in preparation for the move. (Copyright John Dunn Engineering).

The cylinder end covers and pistons have all been temporarily replaced in preparation for the move. (Copyright John Dunn Engineering).

By the end of the day No.8 had been shunted back down the yard and stabled behind the signal cabin in preparation for the move to the AFRPS at Scunthorpe.

Ready for the off. No.8 stands with a barrier wagon in the yard at Murton on Saturday evening. (Copyright John Dunn Engineering).

Ready for the off. No.8 stands with a barrier wagon in the yard at Murton on Saturday evening. (Copyright John Dunn Engineering).

Final Jobs on the ‘Boxes and Preparation for Re-Wheeling.

The final jobs on the axleboxes were relatively straightforward. Paul gave the ‘boxes and keeps a couple of coats of paint; black to the outside and red to the inside of the locomotive. It always amazes me what a difference this makes, all of a sudden it looks as though something has actually been achieved!

You can have any colour you like as long as it's black...... or red! (Copyright John Dunn Engineering).

You can have any colour you like as long as it’s black…… or red! (Copyright John Dunn Engineering).

The keep retaining pins "stamped-up" and in position. (Copyright John Dunn Engineering).

The keep retaining pins “stamped-up” and in position. (Copyright John Dunn Engineering).

 

The pins which retain the keeps were stamped to identify their positions and then everything was thoroughly cleaned, blown through with compressed air, and assembled. The various oil holes were fitted with screwed plugs to keep dirt and grit out; apart from oiling up, these will stay in place until new oil-pipes are fitted.

 

 

 

 

The work on the actual axleboxes was now complete and they were ready to go back on the locomotive.

The finished axleboxes, this face goes to the outside of the locomotive, behind the wheels. The various plugs mentioned in the text can be seen in place on the top. (Copyright John Dunn Engineering).

The finished axleboxes, this face goes to the outside of the locomotive, behind the wheels. The various plugs mentioned in the text can be seen in place on the top. (Copyright John Dunn Engineering).

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Two of the finished axleboxes showing the face which will go to the inside of the locomotive. (Copyright John Dunn Engineering).

We ran out of time last autumn and hadn’t managed to finish the new flange faces on the horns; there were still six of them that needed the edges grinding back and then filing to a finish. This was attended to over a couple of Saturdays and we were then ready for re-wheeling.

Not the best of photographs but it shows the raised edge of the new bronze flange face before it was dressed back. (Copyright John Dunn Engineering).

Not the best of photographs but it shows the raised edge of the new bronze flange face before it was dressed back. (Copyright John Dunn Engineering).

The same after completion. (Copyright John Dunn Engineering).

The same face after completion. (Copyright John Dunn Engineering).

 

 

 

Grooves & Gutters – 3. The Axlebox Brasses.

Because we’ve moved the locomotive we’re a bit out of sync now, but I thought it was important to document what had been done to get things ready for re-wheeling, so I will continue the story over the next couple of posts to bring the  matters up to date.

Lubrication is a massive subject and I did quite a bit of research and a great deal of thinking about the best way to deal with No.8’s axleboxes. The Barclay drawing I have shows two 5/16″ radius oil grooves in the brass. Set at approximately 30 degrees either side of the vertical centre line, these are supplied with oil via 5/16″ diameter oilways which connect to a central well cut into the outside diameter at the top of the brass; oil enters the well via an oil-way inside the crown of the axlebox. The oil grooves are supplemented by an oiler pad located in the keep. As designed, there is no separate feed to the keep.

One of the brasses with both oilways drilled. The drawing in the background was done quickly to give me the angles needed for drilling the oilways but it shows how the design was modified so that the oilway enters the oilgroove from the top rather than the side. (Copyright John Dunn Engineering).

One of the brasses with both oilways drilled. The drawing in the background was done quickly to give me the angles needed for drilling the oilways but it shows how the design was modified so that the oilway enters the oil groove from the top rather than the side. (Copyright John Dunn Engineering).

In an ideal scenario we would dispense with the oil grooves and rely totally on the oiler pad to supply oil to the bearing. I have to be honest, I did not have the nerve to undertake such a major re-design but I did make some modifications. The way Barclays’ had arranged the entry of the oilways into the oil grooves meant that any wear or re-boring of the brasses would have a tendency to break into the oilway; I altered the design slightly in an attempt to prevent this. I also changed the position of the oil grooves. According to various sources, if there is a need to provide oil grooves in a locomotive axlebox brass, then the best position is at an angle of 40 degrees either side of the vertical centre line. This is a relatively minor change of position which was easy to undertake and will hopefully improve the efficiency of the bearing.

 

The milling cutters used for the oil grooves. The one on the left is a conventional 5/8" ball-end cutter, the one on the right has been specially ground to cut the chambers. (Copyright John Dunn Engineering).

The milling cutters used for the oil grooves. The one on the left is a conventional 5/8″ ball-end cutter, the one on the right has been specially ground to cut the chamfers. (Copyright John Dunn Engineering).

 

Barclays’ designed the oil grooves with a slow chamfer on the edges. This is sound practice and is meant to ease the passage of oil from the groove into the bearing. On the smaller grooves in the thrust faces I formed these chamfers with files and scrapers but they are a lot bigger in the brasses so it made sense to grind up a special cutter and mill them. The oil grooves were cut using a 5/8″ ball-end cutter, and then, at the same setting, the tools were swapped and the chamfers milled. The photographs of this series of operations are shown at the end of this post.

 

 

 

Drilling the oilways. The drill in the chuck is a stub drill, the longer drills are on the table ready for use. (Copyright John Dunn Engineering).

Drilling the oilways. The drill in the chuck is a stub drill, the longer drills are on the table ready for use. (Copyright John Dunn Engineering).

 

 

The oilways are fairly deep and gunmetal is notorious for drills “wandering” so they were drilled using a series of 5/16″ drills; starting with a stub, then a jobber and finally a long series. It’s a bit long winded but preferable to having a drill break out in the wrong place!

 

 

 

 

Milling a gutter along the bottom edge of a brass. (Copyright John Dunn Engineering).

Milling a gutter along the bottom edge of a brass. (Copyright John Dunn Engineering).

 

Another modification I made to the original design was to mill a quarter round gutter along either side of the bottom of the brass – at the joint between the brass and the keep. I was concerned that the bottom edge might have a tendency to scrape oil off the journal; the gutters should help to prevent this. I am not certain this was strictly necessary when you look at the various angles involved, but it was reasonably quick and easy to do, and it certainly won’t do any harm.

 

 

All the edges of the oil grooves and the gutters which make contact with the journal were given a slight radius using files and scrapers. This assists the oil in finding its way into the bearing.

First op; milling an oil groove using the ball-end cutter. (Copyright John Dunn Engineering).

First op; milling an oil groove using the ball-end cutter. (Copyright John Dunn Engineering).

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Second op: milling the chamfer using the special cutter. (Copyright John Dunn Engineering).

The finished brasses. The oil grooves and gutters can be seen clearly. (Copyright John Dunn Engineering).

The finished brasses. The oil grooves and gutters can be seen clearly. (Copyright John Dunn Engineering).

Stop Press – We’ve Moved!

We re-wheeled No.8 about three weeks ago and events have moved fast since then. I will continue the details about the way we conducted the various jobs in connection with the axleboxes over the coming weeks.

On Wednesday the 20th of September, after 26 years, No.8 left the Derwent Valley Railway. The decision to move was not taken lightly but was brought on by a number of factors, chiefly the difficulties we have experienced with working in the open air throughout the current major overhaul. There is no acrimony between any of the crew involved with the locomotive and the DVLR Society; the parting is amicable on both sides and we leave with many happy memories.

Our new home is with the Appleby Frodingham Railway Preservation Society who operate within British Steel’s Scunthorpe Steelworks. This is an exciting development for us and we would like to extend our thanks to the A.F.R.P.S and British Steel for offering us this opportunity. We are looking forward to integrating with the society, helping with their projects and continuing No.8’s overhaul.

The following photographs tell the story:

No. * being pushed onto the low-loader in the yard at Murton Park. (Copyright Jonathan D. Stockwell)

No.8 being pushed onto the low-loader in the yard at Murton Park. (Copyright Jonathan D. Stockwell)

On the motorway near Whitley Bridge. We used Calkeld Heavy Transport for the move, they were professional in their approach to the job and we would certainly use them again. (Copyright Jonathan D. Stockwell).

On the motorway near Whitley Bridge. We used Calkeld Heavy Transport for the move, they were professional in their approach to the job and we would certainly use them again. (Copyright Jonathan D. Stockwell).

Another shot of the locomotive "on the move", this time from a more usual viewpoint. (Copyright Jonathan D. Stockwell).

Another shot of the locomotive “on the move”, this time from a more usual viewpoint. (Copyright Jonathan D. Stockwell).

On British Steel metals and entering the A.F.R.P.S. shed; the first time she's been inside a shed since leaving Dairycoates depot in 1991. (Copyright John Dunn Engineering).

On British Steel metals and entering the A.F.R.P.S. shed; the first time she’s been inside a shed since leaving Dairycoates depot in 1991. (Copyright John Dunn Engineering).

Settled inside the shed and ready for work to commence. (Copyright Jonathan D. Stockwell).

Settled inside the shed and ready for work to commence. (Copyright Jonathan D. Stockwell).

A very relieved and happy crew, minus one - Jonathan was taking the photograph! L to R: John Dunn, Mike Sugden, Stuart Stockwell, Paul Cheeseman. (Copyright Jonathan D. Stockwell).

A very relieved and happy crew, minus one – Jonathan was taking the photograph! L to R: John Dunn, Mike Sugden, Stuart Stockwell, Paul Cheeseman. (Copyright Jonathan D. Stockwell).

Grooves & Gutters – 2. The Thrust Faces.

As far as I can tell, no arrangement was made for introducing oil to the thrust faces as a standard feature. When I visited the Barclay Archive at Glasgow University I found a rough tracing which appeared to be a proposal for delivering oil to the thrust faces on No. 2295 but there was no further information; I assume that the idea was not pursued but if anyone knows anything to the contrary I would be keen to know. I applied for a copy of the tracing but for some reason I was sent the wrong drawing. It proved difficult to sort the issue out so I didn’t pursue the matter.

Milling the thrust face oil-grooves. (Copyright John Dunn Engineering).

Milling the thrust face oil-grooves. (Copyright John Dunn Engineering).

It seems sensible to provide a better means of lubricating the thrust faces than relying on the driver’s oilcan but in reality, it’s not that easy to do. I looked at various options; in the end the only practical solution appeared to involve devising a means of conveying oil directly to the face although there were problems with this. The obvious place to position any oilpipes and fittings would be the top of the axlebox on the outside edge, immediately above the point of delivery. Unfortunately the proximity of the frames and the brackets for the spring pin bushes precludes this so a different access point had to be found. Another problem is the 1/32″ gap between the outside radius on the flange of the bearing brass and the inside radius on the thrust face. This is present to ensure the brass makes contact with the axlebox where it should, in the centre of the crown of the ‘box, but it has the effect of providing a ready escape route for oil and it would have been foolhardy to break into it with any oil-grooves; it’s bad enough that the oil has to find its way across.

This photograph shows the top of the axlebox whilst is was set up on the horizontal borer. The 3/8"BSP hole for the oil feed to the horns is the one at the top left with the marking out fluid around it. (Copyright John Dunn Engineering).

This photograph shows the top of the axlebox whilst is was set up on the horizontal borer. The 3/8″BSP hole for the oil feed to the thrust faces is the one at the top left with the marking out fluid around it. (Copyright John Dunn Engineering).

 

After a great deal of thought the design we finalised on was based on what I could remember of the tracing in the Archive plus a great deal of head scratching. A 3/8″ BSP hole was drilled and tapped through the crown of the ‘box in a position, and at an angle, which allows easy entry for any pipe work and gives adequate clearance from the frames, spring-pin brackets etc. Immediately beneath the 3/8″ BSP hole a “well” was drilled in the top of the brass, and this is connected to the thrust face by means of a 1/4″ diameter horizontal oilway.

 

 

 

The oil grooves which feed the thrust faces can be seen on the bottom two brasses in this photograph. The top two show the "wells" referred to in the text. The thrust face "wells" are the smaller diameter ones off-set from the centreline. (Copyright John Dunn Engineering).

The oil grooves which feed the thrust faces can be seen on the bottom two brasses in this photograph. The top two show the “wells” referred to in the text. The thrust face “wells” are the smaller diameter ones off-set from the centreline. (Copyright John Dunn Engineering).

The thrust face oil-groove arrangement was another conundrum. The best place to introduce oil on this type of bearing is as near to the centre as possible, centrifugal force then helps to spread the oil across the face, but it was impossible to get the oilway directly from the “well” to a suitable point of delivery. In the end, compromise was the order of the day; the design that was eventually settled on can be seen in the photographs. Although an odd shape and rather lengthy, it maximises the spread of oil from a point near to the journal in the centre right out to a diameter of 10-1/2″; the thrust faces are 13-1/2″ diameter, hopefully centrifugal force will do its job for the last 1-1/2″.

 

 

One of the vertical gutters. It is stopped short of the edge at the bottom to prevent oil escaping and to help it enter the bearing. (Copyright John Dunn Engineering).

One of the vertical gutters. It is stopped short of the edge at the bottom to prevent oil escaping and to help it enter the bearing. (Copyright John Dunn Engineering).

One of the enemies of lubrication is a square edge because it has a tendency to wipe oil off the surfaces being lubricated, an angle or a radius is to be preferred because they force the oil into the gap between the two bearing surfaces. There are a few square edges on each of the thrust faces; one is the long vertical joint line where the keep is recessed behind the thrust-face, the other is the short, horizontal, outside edge at the bottom of the bearing brass. Quarter-round gutters were milled along the length of these edges, these were left closed at each end and will hopefully help to retain and direct the oil to where it is required.

 

The final job on the grooves and gutters involved breaking the sharp corners on the edges by forming a small radius with files and scrapers. This eases the passage of the oil from the groove into the bearing.

The oil-groove and gutter arrangement for the thrust faces can be seen in this photograph of the finished 'boxes. (Copyright John Dunn Engineering).

The oil-groove and gutter arrangement for the thrust faces can be seen in this photograph of the finished ‘boxes. (Copyright John Dunn Engineering).

Grooves & Gutters : 1. The Horns.

As far as the work on the actual axleboxes are concerned, the end is definitely in sight now. One of the jobs left to undertake is the provision of the oil-ways, grooves and gutters which allow oil to be delivered and distributed across the various bearing surfaces. There are three areas of the axlebox that require lubrication; the bearing brass, the thrust face and the horn cheeks.

This is quite a big subject and it will take two or three posts to explain what has been done and why.

On the Barclay axlebox drawing I have there is a 1/16″ x 1″ chamfer which extends across the top of each horn cheek; oil is delivered to the chamfer by oil-can and then finds its way into the gap between the two faces. I don’t have a drawing of the horns but I did see one whilst doing some research at the Archive; from memory there was a triangular shaped oil-groove cut into the top face of each horn to assist with oil retention and distribution. This arrangement is simple, practical and would have been cheap to produce. It does, however, have a definite disadvantage; any dirt and grit present on the top of the axlebox will be flushed into the gap every time oil is applied and the resulting grinding paste cannot be particularly helpful to bearing life.

Figure of Eight Oil-Grooves.

The figure of eight oil-grooves as described here. (Copyright John Dunn Engineering).

I felt that a better solution would be to introduce oil directly into the bearing, this prevents the oil getting contaminated and also tends to flush grit out rather than in. Oil will be supplied from an oil-box sited either in the cab or on the running plate. Hopefully this arrangement will be an improvement and will extend the life of the horn faces. I am certain Barclays had considered this as an option because there are signs of a similar system on the drawing I have. In this case it has been erased and I suspect a customer has asked for a modification to the “standard” at some point. To be fair, Barclays were working in a competitive market and would have been very cost conscious, they needed to make things simple in an effort to keep production costs as low as possible. I suspect anything more than “standard” would have been willingly undertaken, but at extra cost to the customer.

Trepanning the oil-grooves.

Trepanning the oil-grooves. 1/4″ wide tool ground to a radius and plunged in to depth. (Copyright John Dunn Engineering).

I wanted to make things as easy for myself as Icould so it made sense to machine the groove in the horn cheeks on the ‘boxes rather than attempting to do something with the horn faces on the locomotive. I also wanted to maximise the spread of the oil so needed to cover a fairly large area with the oil-grooves. The most practical solution seemed to be the figure of eight arrangement shown in the photographs. This arrangement was easily cut on the milling machine using a trepanning tool and it only needed one set-up; straight oil grooves which covered the same area would have needed several set-ups to get the grooves at the correct angles.

The 1/4" BSP tapped holes at the top of each horn cheek can be seen in this photograph. (Copyright John Dunn Engineering).

The 1/4″ BSP tapped holes at the top of each horn cheek can be seen in this photograph. (Copyright John Dunn Engineering).

 

 

Oil is fed to the grooves via a 1/4″ diameter hole; this, in turn, connects to a 1/4″ BSP hole which was drilled and tapped into the axlebox at the top of each horn cheek. A fitting will be screwed into the hole and this will connect to a flexible pipe which will provide the link to the copper tubing on the frames.

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Finishing the Keeps.

Finishing the keeps was a straightforward job but before I detail what was done some explanation might be useful.

Two of the axleboxes with the keeps replaced. The outside face of each keep is now set-back rom the thrust face as a result of the operations described here. (Copyright John Dunn Engineering).

Two of the axleboxes with the keeps replaced. The outside face of each keep is now set-back rom the thrust face as a result of the operations described here. (Copyright John Dunn Engineering).

When we started the axleboxes the wear on the outside faces was the same on both thrust faces and keeps. In effect, the keeps had been forming part of the bearing surface and had been taking a share of the side load on the axleboxes. I thought this was intentional and my aim was to create new faces where both the thrust face and the outside face of the keep were level with each other, thus forming a single large bearing surface. Later, when I had the opportunity to study various axlebox drawings, I began to doubt the wisdom of this assumption. My error was eventually confirmed when we got access to the relevant axlebox drawing from the Barclay Archive; the faces of the keeps were supposed to be stepped back, behind the faces of the ‘boxes.

It appears that in a lot of cases the outside face of the keep is set back, behind the outside face of the axlebox; it takes no part in the bearing action of the thrust face. I am not too sure of the reasons for this, I have one or two theories but this part of the job has shown the danger of making assumptions, so if anybody out there has the definitive answer please don’t hesitate to get in touch.

Milling the outside face of the keep. (Copyright John Dunn Engineering).

Milling the outside face of the keep. (Copyright John Dunn Engineering).

 

Anyway, back to the story! As detailed in previous posts, the keeps had been faced and bored at the same time as the axleboxes which meant the outside face was level with the thrust face and the bore was the same as that for the brass. The internal radius on the keep needed to be increased to make certain that it would not rub on the journal; the outside face needed to be reduced to achieve the required clearance behind the thrust face.

 

 

Boring out the radius to give clearance on the journal. (Copyright John Dunn Engineering).

Boring out the radius to give clearance on the journal. (Copyright John Dunn Engineering).

 

The keeps were set-up on the borer as shown in the photographs. Some shimming was necessary to get everything square and then it was a simple case of milling the right amount off the outside face. The radius was bored out and the job was finished by milling the two edges parallel and blending them into the radius. None of these dimensions is critical, they are clearances, so it was a fairly easy and quick job; in fact the setting up took almost as long as the actual machining.

 

Boring and Facing.

The left leading axlebox after the boring and facing operations had been completed. The way this was achieved is explained below. (Copyright John Dunn Engineering).

The left leading axlebox after the boring and facing operations had been completed. The way this was achieved is explained below. (Copyright John Dunn Engineering).

We were now at the point where all of the individual components which make up an axlebox had been either repaired or replaced, fitted together, assembled and we were ready to machine the bearing bores and thrust faces to size. This is a relatively straightforward operation, the crucial element is getting the bores in the right place and making sure everything finishes to the correct dimensions.

Dealing first with the bore: the vertical centre-line was set by Barclays on the drawing and, because the brasses were new and the dimension achieved the required “160º bearing”, there was no need to alter this in any way. The horizontal position was a different matter altogether; this was influenced by the work undertaken on the horns, the horn cheeks on the ‘boxes, and the need to take into account the bend in the frames. In order to get the two axles parallel and in the correct position relative to the cylinders it was necessary to bore the axleboxes slightly off centre, the actual amount varied depending on the ‘box. I would have preferred this not to be the case but I couldn’t make things work any other way; and I understand it wasn’t that uncommon on BR so I didn’t lose too much sleep over it.

The left leading axlebox set up and ready for boring and facing.

The left leading axlebox set up and ready for boring and facing. (Copyright John Dunn Engineering).

The thickness of the thrust faces was determined by a combination of things. Once again the bend in the frames was a major factor, but the amount of wear on the flange faces of both the horns and the ‘boxes, and the steps taken to deal with this, also had to be taken into account. The clearance between the axlebox and the back of the wheel is set by the thickness of the thrust face so it was important to get this correct because it affects the riding of the locomotive.

Roughing out the bore. The tool is cutting into the replacement face on the keep as well as the actual bearing surface, this gives a true circle which makes measuring easier. The keep will be bored out to give clearance in a later operation. (Copyright John Dunn Engineering).

Roughing out the bore. The tool is cutting into the replacement face on the keep as well as the actual bearing surface, this gives a true circle which makes measuring easier. The keep will be bored out to give clearance in a later operation. (Copyright John Dunn Engineering).

 

 

The various dimensions had all been calculated from the measurements we obtained a while ago (see previous posts), they had also been verified by doing a CAD drawing so hopefully they will be correct. I would have liked to have tried the axleboxes in position at this stage, this would have allowed a further check on the relative positions, but I was put-off by the logistics of humping the four ‘boxes all the way to Murton coupled with the time factor. Time will be the judge of whether this was the correct decision!

 

 

The finishing cut being undertaken on the bore. (Copyright John Dunn Engineering).

The finishing cut being undertaken on the bore. (Copyright John Dunn Engineering).

Each axlebox was placed on the horizontal borer so that one of the horn cheeks was on a pair of parallels. This face was used as the horizontal datum and it corresponded to whichever of the horn faces had been used as the datum when setting up and taking measurements on the locomotive. The vertical datum was taken as the bottom faces of the brass. The position of the centre-line of the bore was set from the datums and it was then just a case of boring the brass to the right size to give the required clearance on the journal. I had deliberately made the replacement faces on the keeps slightly undersize on the bore so it was possible to use these as a reference point to measure the diameter whilst boring the brasses; it just kept things simple!

 

Roughing the thrust face to size. (Copyright John Dunn Engineering).

Roughing the thrust face to size. (Copyright John Dunn Engineering).

 

 

Once the bore had been completed the thrust face was machined at the same setting to keep everything square. The critical dimension here was the distance from the outside face of the axlebox, an easy measurement to take.

 

 

 

 

The 'box has been turned around and the inside of the brass is being faced to size. (Copyright John Dunn Engineering).

The ‘box has been turned around and the inside of the brass is being faced to size. (Copyright John Dunn Engineering).

 

The axlebox was now turned through 180° and re-clamped on the same horn cheek as before. This was to allow the inside face of the brass to be faced to size. These were all a straightforward operation and were finished “to drawing”, i.e. 1/32″ proud of the inside face of the ‘box.

 

 

 

 

 

The next stage involves some finishing work on the keeps but I will detail this in my next post.