OVERHAUL 2015 - 2022
Notes from information supplied by Darrin Crone, Locomotive Engineer.
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July to September 2018.
24 September 2018
The superheater header was resealed and pressure tested successfully so the witnessed test was reorganised and a calibrated gauge hired. As it was raining heavily outside it was decided to do the witnessed test inside. A bit of a gamble as if the header leaked we could have been left with a lot of water to mop up. Fortunately it stayed tight while it was left at just above the specified hydraulic pressure for in excess of the specified test period. The sealing and testing of the header has been carried out entirely one of our Engineering Team volunteers who must be thanked for stoically sticking with the project to completion. This particular volunteer is a very skilled member of the Engineering Team who was quickly moved on to another job requiring great care, the final finishing of the outside crank pins.
The driving axleboxes have now been returned from NYMR Grosmont and our journal discs have been machined at York to the current diameters of the coupled wheel journals. This allows us to check the machined diameter of the axleboxes. At Grosmont one of our other axleboxes is on the borer ready to machine, however no further progress has been made for the last couple of weeks.
The loco mounted bogie side bearers, have previously been machined and trial fitted. They are now being reamed in position in preparation for fitted bolts. The volunteer leading this job has declared himself satisfied with the reaming, so it must be good. The bottom plates on the bearers have been dressed ready for machining and welding in position.
Good progress has been made with the painting of the tender wheelsets, while further descaling of the tender frames and dragbox has taken place.
The tender tank has had more material cut out of it to find the start of sound material from which new plate can be inserted. Work has now moved to the space around the water filler. At the front of the tender tank the supporting beam the the tank is resting on, was moved back to allow access to the plate on the bottom front of the tank. Prior to this the bottom of the tank had been painted to primer. The plate at the front can now be accessed fully and sections will have to be removed as it is corroded beyond further use.
When moving the beam back it had to clear the brake brackets on the bottom of the tank. The removed vacuum cylinder brackets are wasted through corrosion and have been thickened by rebuilding with weld.
Progress has been made with the slidebar shims with more done on the surface grinder, while work has continued on measuring the tender frames and wheelsets.
The tender spring hangers and spencer spring boxes and plates have now all been descaled and stripped.
The tender drawhook and its long bolt have been di-pen inspected and no faults found, though it has yet to be dimensionaly checked for wear.
The piping along the inside of the right Cartazzi frames has been extensively reorganised and Peter Ellis has now declared it completed. Attention is now turning to running the pipework to the air pump governor which has been relocated to the right side of the locomotive.
The loco front hook has been machined at York to add more thread to return it to Doncaster pattern and to allow the original rubber spring configuration to be fitted. The cotter slot in the hook has now also been machined.
The leading safety valve parts used for the manufacture of the new top were collected from the contractor where the top was made. The fit of the top was checked on the body and is satisfactory.
The valve rings have been tried in the valve chests and they seem to be OK. The rings are now being deburred and surfaces polished.
The steam sands valve mounted on the reverser stand was given a little grinding in and repacked and is ready for refitting. A new key for the reverser handle was also made and fitted. The last split pins have been fitted to the fasteners around the reverser.
10 September 2018
The end plates for the air pump lubricator drive cylinder have now been machined to size allowing the final assembly of the cylinder.
Painting has continued on the tender wheelsets with undercoat now being applied to the wheels centres.
After modifying the end sealing of the superheater it was again tested. Unfortunately it only made it to 100 psi. As a result the sealing has had to be redone. It now awaits pressure testing again to make sure it can achieve the specified test pressure. Disappointingly the witnessed test for next week has had to be cancelled until we are sure that the sealing can withstand the test pressure.
Work on the tender frames continues with needle gunning around the brackets and angles. All the hornstays have now been removed and all paint removed from the stays and where they fasten on to the frames. Any remaining grime and paint has been removed from the frames around the stays.
Under the tender tank and across the front plate has now been ultrasonically thickness tested and the results are being recorded. The bottom plate and sump have also been inspected inside and out and are sound, however the tender front and the bottom plate toward the front are in poor condition and will require repair.
In the water filler space needle gunning and grinder have been used around the corroded plates and we are still planning the best way to repair this area. Meanwhile some final welding has been carried out along the seams of the corridor roof inside the corridor. The tops of the welds have been ground back on the vestibule support rods welded last week ready for machining.
Measuring around the tender wheelsets continued this week. This is so we can identify repair work and any adjustments that may be required to the tender running gear.
The spring hanger brackets returned to York after being bored to take new bushes in the holes where the spring buckles are pinned. One requires some further work as when inspected the bore wasn't good enough. It's a tough job as the material hardens differently around the bore. All have been di-pen inspected and are free from defects.
The vacuum release valve was fitted to the reverser column after a little lapping in. The steam sands valve is mounted to a bracket on the back of the column. This was stripped and inspected and will require machining, this is now underway.
The end covers from the crankpins were retrieved from store this week. They are required to be fitted so that the length of the bushes to be fitted in the rods can be calculated. They were cleaned when removed from the loco so with a little detail cleaning and preparation were di-pen inspected. They can now be fitted. The trailing crank pins do not have caps but have the speedo crank and lubricator drive crank with nut. These were retrieved from store and separated from their associated mechanisms. They were cleaned and will be fitted to the ends of the cranks.
The expansion link bearing housing that required repair has been worked on to return it to round and removed the taper. A bush has also been made but is yet to be fitted.
The new rings for the pistons and valves were delivered this week and a very good job they look too. The piston rings have been tried in the bores to ensure the gap is satisfactory. The valve rings will be checked next.
The new top body for the leading safety valve has now been machined and would look good on any mantelpiece. It has been dimensionally checked but has yet to be tried on the lower body to check the fit of the thread.
3 September 2018
The air pump lubricator drive pneumatic cylinder has now been fitted to the lubricator and has been satisfactorily tested on compressed air. The end plates on the cylinder are now being finished to size.
Work continues on the tender with more needle gunning and wire brushing. This not only includes the frames but also the removed components. The spring gear is being methodically worked through, while the draw gear has been wire brushed and the buckeye coupler cleaned. The vestibule support rods show much wear and it was decided to weld repair them rather than produce new ones. The areas requiring rebuilding were marked up and have now been welded.
The frames still require further needle gunning. A number of 007 Gang members have come in on extra days during their summer holidays to put time in to needle gunning the frames.
The tender corridor roof is completed except for the short section at the cab end which will be left until the tender front is repaired. So attention has now turned to the water filler space. The air tanks and other air system components in this area were removed. The area then needed cleaning out. Further work is required in here to get down to the bare metal to find sound material from which we can start repairs.
At the front of the tender the large cast iron weight that also forms the step into the corridor has now been removed. This exposes the tender front where it joins the bottom plate. The front of the tender can now be descaled and thickness tested.
The tender wheelsets are being cleaned off and are now receiving their first coats of primer, and further work is being done to get down to sound material on the tender brake cylinder mounting brackets.
The reverser stand is effectively completed. The reverser lock hand lever has been fitted and the linkage connected. The final coats of paint have also been applied.
The last of the large studs used to secure the footplating to the slidebar brackets and cylinder castings was fitted this week.
The loco bogie side bearer installation continued with prepping the right hand plates for tacking. The plates were put back on the engine and clamped in position then tacked. The left and right have both now been welded. The side plates were then cut to shape. They have also now been machined to level them and been trial fitted to check their alignment. When pinned back in position they are tight against the bottom of the frames, and when checked with a spirit level are level with the loco bogie stretcher both across the loco and fore and aft. Exactly what we want.
The sealing and testing of the superheater header has been continued. For the higher pressure tests we now need to carry out, some of the rubber gaskets have been replaced it has now held pressure well in excess of 300psi. In fact a higher pressure gauge is now required. A date has now been fixed for its final pressure test when an inspector will be present to witness the test.
Re-piping around the frames where the ashpan is fitted is being continued. This has involved the redesign of the pipe runs down the left inside of the Cartazzi frames.
The work on measuring for new pins and bushes for the valve gear has continued. The expansion link trunion bearing covers have previously been straightened and the countersunk holes for the fixing screws tidied up. New screws have now been made and trial fitted. Each is specific to its location and had to be individually fitted.
The surface grinding of the slidebar shims has now been started, and the inspection of the conjugated valve gear.
The driving axleboxes have now been finish machined. It is planned to machine the trailing set next. In preparation for their return the spring hangers that are pinned to the bottom of the axleboxes have been retrieved from store. They had been cleaned and wire brushed when removed from the loco. They have now been di-pen inspected. The bushes in the hangers will require replacement but first the hangers will require boring out to return the holes to round. A sample has been done satisfactorily and the remaining five will now be treated similarly. Other work on the hangers will be the replacement of one of the large pins than goes through the hanger and bottom of the axlebox.
20 August 2018
At the beginning of the week the a number of items were sent to Llangollen to join the boiler. The major items were the ashpan and smokebox door. Later in the week I and our CME went over to Llangollen to look at progress on the boiler. It is still upside down which will allow the ashpan to be lowered on to the foundation ring and should make fitting it easier.
It is the first time I have seen the boiler with the foundation ring back in position and progress has been made in fitting all the rivets and trimming and caulking the plates. Work continues on caulking and dressing the rivet heads on the outside of the foundation ring. The gauge frames have been tried in place and gauge glasses tried in during our visit to ensure the frames line up so that the glass tubes are not fouled. Everything appears to be OK.
Whilst there the regulator stuffing box was removed and the flange face on the boiler was examined. This is a critical joint that in service is very difficult to get to. The face has been fitted accurately to the stuffing box after it was repaired.
One of the main purposes of our visit was to discuss the final testing of the boiler, to ensure all parties expect the same procedure. We plan to test many of our boiler fittings on the boiler so that they are proved during testing and this was discussed.
We had hoped to send the superheater header to Llangollen on the same transport but we want to test it to higher pressures than we have yet achieved. During testing we had trouble maintaining pressure in excess of 250psi due to a seal extruding from below a sealing plate. This was identified as being caused by the plate flexing. New thicker plates were obtained and they have been drilled to fit them. A bit of work was also required to get one of the plates to sit flat on its gasket. All is now ready to be resealed and tested again.
Work has progressed on the loco bogie side bearers. The left side was tacked up on the loco on Wednesday. The locating pins were then driven out and the assembly welded up on the bench. Meanwhile the last hole in the right bearer was drilled through to final drill size. These plates have now been taken down and prepped for welding.
The corridor roof on the tender has seen the last replacement section against the coal division plate trimmed to size and fitted. Work on the corridor in the water filler space will be confined to patching as the plate here is in better condition.
Much effort has been put in to descaling and cleaning the bottom of the tank. The bottom plate forms the bottom of the tank and the foundation on which the tank is built. Now exposed it will be thickness tested. The sump replaced in the 1980s seems sound but toward the front of the tank and around the sides where the frame brackets are there are signs of corrosion.
Measuring of the tender frames, axleboxes and wheelsets is ongoing under the guidance of our CME.
The reverser stand has now been painted to top coat gloss. A coat takes about half a day to apply as much of it has to be done with a small brush to fit in around the screw shaft.
All the new thrusts have now been fitted to the axleboxes, and the first axlebox had been put up on the horizontal borer at Grosmont MPD. I and our CME went to Grosmont to confirm our instructions for the machining of the axleboxes. At the end of the meeting we were confident that the boxes will be machined to our requirements. It is expected that the driving boxes will be completed first, followed by the trailing pair.
13 August 2018
The needle gunning of the tender frames has continued concentrating on the brackets and angles on the outside of the right hand frames. One of the 007 gang came in during his summer holidays and between helping to trial fit the ashpan, needle gunned a section of the inside of the right frame near the rear dragbox. The tender tank bottom and sump have been needle gunned. A tough job working overhead. The plate is now paint and scale free and can be examined for thickness.
The tender corridor connection is supported at the bottom and extended by square section, spring loaded rods. The rods are guided by adjustable wedges to take up the wear on the rods. All this assembly has now been removed as it shows signs of wear and corrosion. Where the corridor roof sections have been welded in the struts across the corridor that support the side of the tender have been removed.
A start has been made on the lengthy process of assessing the tender axleboxes, journals and bearings. The leading axleboxes and bearings have been measured and the clearances calculated. The clearances will be compared to specifications and any necessary refurbishment identified.
Further work has been done filling the driving wheelset and some of the filled patches have received primer. Progress with this has been slow due to the low priority of this job. The reverser column is now painted to undercoat. The feedback linkage that operates the cut off indicator on the backhead, in front of the driver has also been assembled in the reverser column.
The bogie underkeeps have now all been fitted with boss face oiler felt pads. The large oiler pads that sit in the underkeep oil bath and oil the journals have all been soaked in oil and fitted in the underkeeps. All the underkeeps are now fitted in the bogie axleboxes. The bogie top bearing plates have been collected from the suppliers.
Drilling through the loco bogie side bearer plates has gone well. The left side plates are now drilled to a large size, just short of the final diameter which will be reamed at final fitting. The left side plates have been prepped for welding.
The ashpan damper door and screen are finish welded in their new positions. They were removed from the ashpan for the trial fit. It was the purpose of trial fitting the ashpan to reproduce the path it would take when attached to the boiler, which would not allow the ashpan to be inclined as is required for fitting when the damper door is attached. The cab required removal first then the ashpan was lifted in to the frames horizontally, as it would be when attached to the boiler. Sounds easy but the ashpan has first to be moved under the crane by pushing it outside of the workshop to enter a set of doors where the crane can be accessed.
The ashpan was lifted in to the frames lowering it slowly so that any clash with the pipework could be identified. With a little movement from side to side the ashpan reached the estimated correct position when it will be fitted with the boiler. The simulation continued to ensure that the damper door and screen, and hopper door could be fitted in situ. It's not easy but the volunteer Engineering Team managed it.
Once the ashpan was in position and all parts fitted, the pipework was examined all round and a couple of areas were identified where we plan to provide more clearance. Then the damper and hopper doors were removed and the ashpan lifted from the frames. With the ashpan safely back on the ground a couple of jobs were identified. To allow easier assembly of the damper door assembly washers have been welded inside the ashpan so that the hinge door bolts can be tightened more easily from inside the ashpan. Also strips of steel have been welded beneath the hinges to provide easier location of the hinges during assembly inside the frames. With these jobs complete the road transport has now been booked for taking the ashpan and smokebox door to Llangollen. To give an indication of the labour intensive nature of our work it took a full day by a full team to trial fit the ashpan.
No time has been lost it addressing the pipes we require tweaking to provide more ashpan clearance. Unfortunately the work on one of the pipes has required the removal of a considerable number of other pipes.
The superheater header has now been sealed up and tested. At last the day came to fill it with water and pump up the pressure. At the first attempt it made it to 220 psi before one of the seals extruded from below a flange. After remaking the seal we manged to get 250 psi. While stood there with the pressure solid as a rock we took some photographs and inspected the repairs that have been made to the header. Apart from a few weeps from seals the repairs appeared to be tight. After a while one of the seals again gave way and started to leak. It was identified that thicker plate would be necessary to seal the port that gave us problems with the sealing. This plate is now on order and when fitted the header will be retested. It is a little disappointing that it won't now go on the truck to Llangollen next week, but it was an achievement to have it standing at full boiler pressure and very pleasing that all the repair work done was sound.
The expansion link outer plates have received further inspection in the corners where the mounting pads join the main plate. This has required cleaning and dressing with great care. These areas are known to have cracked on other locomotives and with the corners being sharp, and with machining marks it is difficult to identify small cracks. After smoothing off machining marks, scratches and marks, we are now reassured that ours a defect free.
With the expansion links, valve gear work continued with the removal of the lining in the right expansion link bracket. The lining did not give a good fit to the bearing, however when the lining was removed the hole in the bracket was found to be worn out of round and tapered. The bracket hole will need attention before a new lining bush can be fitted and expected to be a good fit on the bearing.
The squares on the driving wheels are now being checked for their set angle. Not an easy job to measure the angle of a square set some distance from the surface of the wheel. When the angle is determined we will know what correction, if any, will be required on the return crank.
29 July 2018
The driving wheelset was brought back in to the workshop this week and returned to its usual place in front of the loco. Moving the wheelset in and out of the workshop on cranes has damaged some of the paintwork so the Painting Team has begun to make repairs to the paint to restore its finish to our standards.
The reverser column vacuum release handle was fitted requiring careful filing to shape this week, as the reverser nut on which it is mounted has now been finished. This has included fitting a new bearing in the nut housing and re-machining the housing so that shimming is no longer required.
The reverser screw was painted this week and assembled in to the reverser column. A new bush was made for the reverser crank at the bottom of the screw. This was pressed in this week and the crank also fitted to the reverser column.
Work progressed on the tender frames this week with further needle gunning of the frames. Now we are on to the brackets progress has slowed. The remaining pipework in the tender frames has been documented. After this was done the steam heat pipe was removed and the end pipes from the vacuum brake pipe run. The section of brake pipe at the front of the tender will require replacement due to corrosion. A number of flanges from the condemned pipework have been recovered and may be reused.
The TPWS junction boxes at the front and rear of the tender frames were removed. The internal connections have been carefully documented and the ends of the conduit bagged to protect the cable terminations. It had been hoped to leave this assembly in place, however the aluminium junction boxes have not survived the last period in traffic very well with the leading one certainly requiring replacement due to corrosion. Some of the conduit will also require renewal.
The leading rubber spring assembly was removed from the trailing tender dragbox this week and the adjusting wedges for the corridor connection bottom supports. All these components will require assessment. Removal of these components will allow full inspection of the trailing dragbox and coupling assemblies.
Work began this week on finish welding in the tender corridor roof sections fitted so far.
The right tender vacuum cylinder has been stripped and inspected. The piston rods from left and right cylinders were measured and di-pen inspected with no faults found. The piston rods measured showed less than one thou variation on diameter. As with the left cylinder all the small studs holding the pressure connection flange and the neck seal will require replacement. A list of replacement seals has been made.
The bogie underkeep trays were re-positioned this week. The securing lugs were cut off and bolted to the axleboxes, then the tray sections were carefully positioned relative to the wheel face of the axleboxes. The lugs were then tack welded on, in situ. The underkeeps were then removed and finish welded all round on the bench. When welding something like this I would expect the lugs to move during welding and have to do a lot of fitting to get them to fit the gap in the axlebox, but a really good job was done by our volunteer welding specialist. The first tray slid straight in with a good close fit on the axlebox lugs. All required a little dressing though, with some sharp edges being removed but all are now fitting correctly. A start has now been made on fitting the wheel boss face oiler pads. These have to be cut to project correctly to contact the wheel to oil it when required, but not be too long to be dragged out by rubbing the wheel too much.
The new rubber springs for behind the front coupling hook were assembled this week. We had previously made an assembly jig to get the rubber ring sections concentric and spaced correctly on the backing plates. It all went very well and the springs are now ready for fitting.
Work on the valve gear components continued this week with the trial fitting of the expansion link trunnion bearings in the housings on the locomotive.
The ashpan screen was refitted this week and only now requires final welding of the tacks. The ashpan will then be trial fitted. It is hoped to send the ashpan to Llangollen soon to take advantage of the boiler being on its back, as it is soon to be turned. It is reported that the throatplate section of the boiler has been welded and that riveting of the foundation ring is progressing.
Work progressed on the loco's bogie side bearers with the first of the bearer plates clamped in position and drilled through using the fitted bushes as a guide.
23 July 2018
The material for the new safety valve top to replace the worn service example was collected from the supplier this week by an Engineering Team volunteer saving us the cost of transport of this substantial and expensive piece of bronze. We have has also been told that the material for the new bottom flanges has also been cast and is ready for collection. The machining will be carried out off site.
Most of this week's efforts have concentrated on the tender, with the frames receiving most man power. The tender frames have been cleaned and scraped, and needle gunning started this week. I was quite looking forward to this as the history of the tender frames will be gradually revealed. There are a number of repairs and welded up holes, and on Saturday we found our first stampings. Towards each end of the frames on each side are oval plates welded in to the frames. They look like lightening or lifting holes that have been filled and one of the filler plates is stamped with various numbers and what looks like the word "approved".
The tender tank has seen further work on the corridor roof with preparation of the new roof sections for final welding. Welding work on the ashpan has taken place this week. This has involved welding up of the damper hinge holes and re-drilling in the position determined when the ashpan was trial fitted in the frames.
To get to the ashpan it was removed from the loco frames this week requiring the usual procedure of taking the cab off first. With the hinges fixed in their final position the lugs require re-fixing to the screen, and that should the ashpan finished as far as we will work on it. However, the ashpan will be trial fitted again and as it does have the habit of growing every time it is removed.
The underneath of the tender tank has received its first real clean off by members of our "007 Gang" of junior volunteers, while others were put on needle gunning the outside of the tender frames. The junior volunteers are developing in to an effective work force, well worth the investment in time we have made in them.
With the cab off the Pipe Fitting Team took the opportunity to fit the reverser stand cab floor plate, and to drill a pipe support bracket. They want to leave the cab off as it aids accessibility for them but we have no where to store it, so it was refitted later in the day.
The loco bogie side bearer fitting proceeded this week with the bushes that go in to the frames fitted. Long series drills have been obtained and a series of larger drills so that drilling through and aligning the components that make up the side bearers can be done.
The plates that go between the tender axleboxes and springs have now all been cleaned up and will be assessed for condition. The return crank rods were also di-pen inspected this week. This continues our refurbishment of the outside valve gear. The reverser screw was inspeceted and will be painted before refitting.
A start was made on the repositioning of the bogie axlebox under keeps, now that the axleboxes are a little shorter, as described in last weeks report. The lugs on the trailing underkeep trays were cut off. These will be tacked on in situ with the tray in the correct position relative to the wheel face of the axlebox. The tray can then be removed and finish welded.
The new AWS carrier rubber bushes were fitted this week to the bogie, allowing the fitting of the shield that goes across the front of the bogie over the AWS carrier bracket.
15 July 2018
Last week we jacked up the tender tank and frames and left them up an the jacking stands or stools. This week the hire equipment had to be returned and unfortunately the stools that the frames were stood on also had to be returned as they were needed for another job. We had already planned to removed the frame stools and had retrieved 4 frame stand screw jacks from the same source as the two used under the front of the locomotive. After a quick clean off and a coat of paint the screw jacks were put under the frames. I initially had doubts about how stable the screw jacks would be, so had hoped we could hang on to the stools, however the screw jacks turned out to be very stable and work has carried on the frames this week with no worries about the stability of the setup.
Work has concentrated on getting a good start on the frames. This week the springs and hangers were removed. The parts are now undergoing cleaning and the springs have been hard marked with their location, preliminary cleaned and moved out of the workshop. The frames have also seen cleaning this week. Inside the frames behind the wheels a considerable amount of dry compacted road grime has been removed. Also around the leading ends of the frames and under the dragbox a considerable amount of scale and corrosion is being removed.
The tender axleboxes and their components have been preliminary cleaned and have been tagged to control and record the work that will be required to these items. The tender wheel journals have been measured as part of the wheelset examination.
At the trailing bufferbeam end the flexible hoses have been removed along with some associated components The rear coupling, including the buckeye were also removed. The rubbers in the coupling are in quite good condition though a number are now life expired.
Two new roof sections have been fitted in to the corridor roof of the tender tank. Not a pleasant task at the moment working high up in the heat of the workshop.
The tender brake cylinders began their examination this week. Starting with the left cylinder, cylinder, cover and piston were separated. The cover studs were die-nutted and the pressure connection flange was removed. Unfortunately the flange studs are life expired and had to be removed and scrapped. One had to be drilled out. All the flange holes have been cleaned out with a tap.
Away from the tender the AWS carrier bushes for the bogie were collected from the suppliers, after rejecting the last supply.
The last of the loco cylinder leading top corner bolts and studs were fitted this week, with the seat dressed so the nut could be put on the last stud.
The position of the ashpan hinges is now finalised after spending some time working overhead tack welding the hinge stop plates with the ashpan in place, and grinding the bottom edge of the door. The ashpan will now require removal and finishing off the engine as there is no access up the side of the ashpan between the frames.
The loco bogie side bearer mounting hole bushes were completed this week. The bushes are now ready for fitting to the loco. The bogie axlebox underkeeps have oiler pads facing the wheel bosses so that the bosses receive oil for when they are running on the axlebox face. The pads are cut from felt but they have to protrude sufficiently to oil the wheel. So Engineering Team volunteers went round the underkeeps to investigate if the underkeep projects beyond the axlebox, which may be possible as the axlebox faces have been machined back. It was found that one of the underkeeps does and will require modification. They took measurements of the other axleboxes and came up with suitable measurements for the oiler pads.
9 July 2018
The two studs for the right cylinder, frame and saddle joint were machined and one is now fitted. Again the faces of the saddle casting require careful preparation to get the seat of the nut to be square to the centre of the stud so that the stud has a straight pull on it without being bent, a probable cause of the previous failures with these fasteners.
On the subject of studs the repair of the footplate studs in the cylinder castings is progressing with material now being machined by to produce the studs. Each is having to be machined specifically for its location. A couple of the existing holes in the slidebar brackets have been plugged and will be drilled and tapped to return them to the original thread size.
I went to collect the new rubber bushes for the bogie AWS bracket, however they have been made from the wrong thickness of material so were rejected. On the positive side progress has been made with the first two of the loco bogie sidebearer bushes. These have now been machined and the plates for the side bearer fabrications are being shaped.
The new rubbers for the front coupling hook have been check over and all is to drawing, so now a jig for the assembly of the rubber springs has been designed.
The overhaul of the reverser stand continues with the reverser nut thrust bearing being replaced. To replace the old bearing the new bearing races were surface ground so that its overall thickness is now the same as the original bearing.
In preparation for the tender lift and frame overhaul the underkeep oil trays were removed and emptied, and so were the underkeep oiler pads. The split pins from the hornstays were also removed. The tender frame guard irons and footsteps were removed from the rear of the frames as we will need to jack there. The last of the pipework that could cause issues during the lift of the tender frames were removed and the components tagged and noted on our schematic. The coupled wheels and bogie were moved as far forward as possible so that as we have as much space as possible for the use of the workshop overhead crane when moving the heavy lifting equipment. The tender was then moved forward to the position where it was planned leave the tender tank on stands.
Elsewhere the tender brakegear is being steadily worked through, being cleaned and needle-gunned.
Little progress has been made with the valve gear over the last t20 weeks due to manpower being directed on to other jobs but we have managed to find time to di-pen inspect the union links.
Our coach is at CTMS at Cranmore for overhaul work and I visited it end of week 26. With the CTMS management we went through the original list of works so that both SNG and CTMS are clear of the work we want to be competed on our coach. The standard of the finish they achieve is very good as displayed by an eastern region 1950's suburban coach standing in the sun outside their works. We have agreed to some minor amendments to the original planned works so CTMS will requote and an amended purchase order will be issued. Work is scheduled to begin in earnest during autumn with our coach being under cover from then until completion, planned for spring next year.
At Llangollen the regulator is finally fitted and the positioning of the regulator reach rod has been measured and is at least two inched clear of the transverse stays. The new throatplate section is clamped in place on the foundation ring and is prepped for welding in.
Most of our time week 27 has been spent on lifting and separating the tender tank and frames. This has required a program of preparation over many weeks, including removal of numerous seized bolts holding the tank down and also pipework and electrical systems. Away from the "tools" there has been a considerable amount of preparation with valuable input received from our Team Leaders. As a result of this effort a risk assessment was completed and after discussions with lifting contractors we devised a procedure. We must thank Paul Gardiner of Durham Lifting for being so generous with his time. Paul planned the lift and supplied all the equipment that would be required, only requiring us to find a few shim plates and use some of our sleeper ends on the day. When the date was firming up for the delivery of the equipment a roster was drawn up and the volunteer Engineering Team rallied so that the roster was soon filled. We were able to devise a plan for the week where everything we wanted to accomplish was, while being unhurried within our normal working hours.
With the arrival of the lifting gear due and the Lift Team in the workshop we had an initial talk though of the procedures and plan for the week. The equipment was delivered later that morning and we were helped by NRM workshop staff who drove the forklift truck. Some of the lifting gear was very substantial with the tender tank beams being 400kg each. With the lifting equipment on the ground the Lift Team moved it in to the workshop. The base stands or stools were moved to the four corners of the tender and the rest of the gear unpacked and divided up. The whole operation being under the direction of Lift Team Leader, who lead the operation until completion three days later.
With the corner base stools in place jacking of the tender tank began. In each corner a team was placed to operate a hydraulic jack and to manipulate packing, as many pieces would be too heavy for a single person to lift. The Lift Team Leader would not be operating a jack as he would be required to coordinate what was happening in the four corners, and to check how the tank was responding overall to the lift.
After each lift of approximately 20 - 25mm the tank was repacked so that in the advent of a jack failure the drop would be no more than this. So the tank is raised slowly with these little steps, slowly but safely. When the tank was raised sufficiently to allow the lifting beams to be inserted across the top of the frames and under the tank, packing between the frames and tank was put in. With this packing in, the jacks could be removed giving clearance to put the beams in, and to reposition the base stools outside of the tank so that eventually the frames would be cleared for rolling out.
The beams are very heavy so were moved on the workshop overhead crane in to the space in front of the locomotive. The crane doesn't have the reach to support the beams until they are on the frames so stools were positioned to give the beams a platform to rest on at frame height. Engine hoists, small mobile hydraulic cranes, were used to "walk" the beams across the stools towards the frames. Eventually, with their weight supported on the frames they were pushed in to position by the Lift Team members.
With the beams in place extension pieces were fastened to their ends which allows the jacks to be positioned for the next stage of the lift. As before small lifts were followed by packing step by step until the bottom of the tender tank and the vacuum cylinders could be seen to clear the frames. A chain was then placed round the tender drawhook and the frames carefully pulled from under the tank. When the frames were clear they were chocked and we treated ourselves to a brief pause for photos. Well it's not often you see a tender tank that high in the air.
The tank was then lowered by removing packing, again in 20 - 25mm steps, paying careful attention to keep all the jacks loaded and maintaining the level of the tank. Eventually the tank was left on the beams on the large base stools, where it will remain until it can be put back on the frames.
With the tank secured we then moved on to lifting the tender frames to release the axleboxes, and also to allow the tender wheels to be rotated sufficiently to allow access to all areas of the inside of the frames and outer surfaces of the wheels. We used the same lifting technique as used on the tank, however accessibility to the bottom of the frames for jacking and packing is not as good as the flat bottom of the tank. Eventually the frames were lifted sufficiently and was left on its packing until it can be lowered back on to the axleboxes.
The lift went very well and thanks must be given to the Lift Team Leader and the team members, most of which were there throughout the three day program.
With the tender tank lifted the vacuum cylinders and their brackets were removed. These will now be evaluated and overhauled. The work on the tender frames has also progressed with the removal and dismantling of the axleboxes.