OVERHAUL 2015 - 2022
Notes from information supplied by Darrin Crone, Locomotive Engineer.
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April to June 2019.
25 June 2019
The ashpan was delivered to York on Tuesday by one of our Engineering Team volunteers. The trailer was reversed into the workshop then manhandled to the crane and the ashpan lifted off. To allow the ashpan to be fitted the cab had to be removed, and to release that some of the installed components around the cab had to be removed, including the structure for the fireman's side platform. We've done this a couple of times now so it was all achieved without too much fuss. With the cab on the floor the ashpan was put down on packing while the hopper and damper doors were fitted.
When assembled the ashpan was lifted and the rear given extra height as the ashpan does not go in as a straight lift. It went in with very little trouble, with our Pipe Fitting Team Leader watching it enter the frames and monitoring its proximity to his pipework. It fits well as best we can judge without the boiler in place. The next step in fitting the ashpan was the fitting of the diaphragm plate, and this is now in place with temporary bolting connecting it to the frames and ashpan.
With the ashpan in we then moved the loco forward as we do not intend to refit the cab until the boiler is on. The loco, now on its bogie and coupled wheelsets moved very easily. When there was enough room the frames were chocked and the cab lifted and placed against the buffer stops behind the loco. A good effort by all in attendance.
The ashpan spray supply pipe fastens to fittings on the rear of the ashpan. They stick out and have received a little damage so these were loosened, then the threads were dressed until the compression nuts on the supply pipe fitted.
The tender springs have now been returned from contractor refurbishment and the spring hanger bolts have also been completed, with the remaining few ready to collect from contractors. The remaining tender bearings have all been white-metalled and are now being machined. With the tender approaching re-wheeling preparation has begun on finishing the painting of the tender frames.
Painting of the cab floor and structure is now underway, which has required the removal of most of the cab pipework. The pipework to the reverser mounted air brake valve has also been removed to allow the removal of the reverser column.
Good progress has been made with the new tender hornstay bolts. Most are now machined with about half machine threaded. New nuts are on order, but it is hoped some of the old can be recovered.
In the tender frames further clamps have been fitted to secure the TPWS conduit and new front junction box is being painted prior to fitting.
At the back of the tender frames new and improved cotters for the vestibule lower support rods are being made. While waiting for the arrival of the new plate for the tender front, more bitumen has been melted out of the rear of the tender tank to allow the welding in of the last plate near the vestibule bottom.
The return crank set up jig is now completed and has been fully assembled on the right driving wheel. Meanwhile the return cranks have been welded and inspected at contractors. Some further welding is required before they are ready to return to York.
Work on the slidebar bolts continues with the middle slidebars nearing completion and the material for the locking "feathers" is on order. Feathers are keys fitted to the bolt that prevent it from turning when the nut it tightened.
Measurements are now being taken of the outside connecting rod big ends so that final dimensions of the big end bearings can be specified.
The fitting of the pin between the reverser column crank and the trailing end of the reach rod continued this week, however it's hard work as the hole in the reverser crank is obscured by the footplate angle, so this has been left for now as the reverser column is to be removed to allow fitting of the boiler. This will allow easier access. So we have moved on to fitting the lifting link die bock pins.
At Llangollen the superheater header has now been mounted in the smokebox and is up on packing pieces on brackets. The joint between the header and front tubeplate is being checked.
21 June 2019
The leading tender wheelset has been assembled with bearings and axleboxes, and was lifted in to the frames. The axleboxes entered easily in to the horn guides and the end float examined. All looks to be in order so the wheelset was returned to the rail. To enable the lift the frame jacks were returned to the front of the frames, which was possible as the brakeshaft trial fitting is now completed. The tender brakeshaft and bearings have been NDT inspected with no defects found and have now been painted.
Now that the method used for the tender axlebox bearing dimensioning has been proved the remaining brasses have gone to contractors for re-metalling and machining. Drawings have been prepared for their machining and these also have been sent. The journal end radius gauges have now been ompleted and these will enable accurate specification of the bearing ends.
The tender axleboxes have been given a clean out and the slipper blocks that the brasses slide on have been retrieved from store, given a wipe over, and are ready for fitting when we get the brasses back.
The upper tender brake hanger pins have had all the threaded holes for grease nipples cleaned out with a tap and blown through to remove any swarf. Grease nipples have been fitted to all the pins. The pins are retained by clips on the outside of the frames and the clips retained by nuts on studs. All the studs have been die-nutted. The trailing clips have been modified to accommodate grease nipples by welding on additional material then accurately drilling through a clearance hole for the nipple. All this work being carried out by our junior volunteer.
When the wheelset was lifted in to position the proximity of the pipe runs were examined and all were found to be clear, well done to the Pipe Fitting Team. Work has progressed in routing the water delivery pipes through the trailing tender dragbox. Work has also been done on routing small pipe to the air brake cab gauges and the governor. The lubrication pipes to the reverser column have been remade.
At the front of the tender the dissection continues. Almost all the tender front plate work above the handbrake shelf has been removed leaving framing and brackets in place. The various fittings on the plate have been removed and are in the process of refurbishment. The coal door frame has been tidied up as best we can on what is probably an original 1928 fitting. New plate has been specified and quotes have been received. The scoop fill indicator siphon assembly have been removed from the tank front and is now in undercoat ready to refit.
At the back of the tender work has continued on the cosmetic refurbishment and the old vestibule handrail cut up to remove the wasted section. Plugs have been made to align the new section of curved handrail and the arrangement has been tried in position.
The reverser reach rod and lifting arms have been refitted to the loco, and linked up to the reverser column. The reverser has been operated against the "clock" spring that counterbalances the weight of the assembly and it feels good. We have new pins for the assembly and the pin between the reach rod and lifting arm has now been fitted after the holes were made a good fit on the new pin. Work progresses on the pin between the reverser column and the trailing end of the reach rod.
The 2:1 lever pivot bearing has been dismantled and inspected. New pins for the conjugated gear have been specified and drawings have gone out for quotation for their manufacture.
New slidebar bolts are now being machined to fit individual positions. New tender hornstay bolting is now being machined with the first off being checked in position. We were happy with the fit and a standard size that will cope with the variation in hornstay thickness around the frames has been specified.
Work continues on the driving outside crank pin set up with dummy return cranks being made and fitted. Other components for the set up jig are being made. The old return cranks are now with contractors for rebuilding with weld and they will then be machined to the dimensions taken off the wheelset by the jig.
The boiler main internal steam pipe has now been successfully hydraulically tested. This test was a requirement of our VAB and insurance company. The superheater header in now fitted and sealing of the header is being carried out to test the joint against the front tubeplate. With the boiler drained the refurbishment of the doors has now been completed.
The porous steam heat valve has been brought back to York. It has now been dismantled and the matter discussed with the supplier. The valve is to be returned and a new body cast and machined.
The ashpan has now left Llangollen and will be delivered to York next week.
The old cast iron external steam pipes were brought back from the pattern makers, and the patterns have now been sent to the foundry. The blast pipe casting has now had its caps removed and de-carboning has begun.
The GSMR enclosure is now being painted after refurbishment and the conduit and wiring from the rear TPWS receiver to the front of the tender has been fitted. A new junction box has been obtained and when fitted this will complete the TPWS installation on the tender.
5 June 2019
Much time has been spent on the back of the tender in filling and sanding. At the front of the tender more material has been cut out. The coal door frame has been removed and been separated from scrap pieces of tender front and has had all its rivets removed. The strap put on when the front of the tender had its height increased to match the A4 cab profile has also been removed, and will be refitted after the new tender front platework is installed.
Work continues on the refurbishment of the tender front locker that was adapted to house the GSMR radio unit.
The lower tender vestibule support rods have now been machined to size after being rebuilt with weld. Work will now proceed on recovering the bufferbeam housings to be a good fit on the rods. The sections of new steel in the vestibule bellows flange have now had their welds ground flush and attachment holes drilled through.
Work on the pipe system continues with the routing the water filler pipes through the frames and trailing dragbox. Work also progresses on routing the large air pipe through the frames that goes to the tender top air tanks. Work has started on the manufacture of new pipe ends for the atomisers.
The leading set of tender brasses have now been scraped in. The leading set of axleboxes are now fitted to the leading wheelset and are ready for trying in the frames. This has involved moving the jacks at the front of the tender frames which were moved back to allow the trial fitting of the re-bushed tender brake shaft assembly.
The trailing tender brasses have been white-metalled and are now being machined. The end radii being machined to gauges made by a member of the Engineering Team.
The bushes in the tender brake shaft end brackets were machined and fitted. The assembly was tried in place with some final adjustments being made. The assembly is satisfactory and new bolts are now on order for final fitting. The old bushes have been removed from the long pull rods that couple the lower ends of the tender brake hangers and new material to manufacture new bushes is awaiting collection.
Work on the crank axle continues with the middle crank pin now finished with completion of the radius at the right hand end of the journal. A very skilful piece of work carried out by an Engineering Team volunteer on this critical component. The components for the return crank setting jig are now coming together with various parts being machined. Work has begun on fitting the reverser reach rod with the fitting of the rear section.
The leading crankpin caps have been fitted after the re-skimming the left leading. Both caps now have the BR specified clearances. The sizing of the new slidebar bolts continues with the middle slidebars being worked on first. The machined and hardened motion pins for the outside gear have now been completed and collected from contractors.
The boiler was steam tested this week at Llangollen. Unfortunately the new steam heat valve leaked from the body casting so the test was stopped before the setting of the safety valves. The testing of the boiler was successful and in particular the front tubeplate was dry as a bone which means that the installation of the superheater can begin.
The superheater header sealing kit was delivered to Llangollen by one of our volunteers in preparation for the hydraulic test of the superheater in situ, and clamps used to seal off the regulator have been sent to enable the hydraulic test of the main steam pipe.
23 May 2019
The removed parts from the front of the tender are being cleaned and descaled. These parts include the coal door and gate. At the back of the tender tank the new shim plate that runs across the rear flange of the tank and the vestibule door plate are now painted. Work has started on grinding the screw heads flush with the tender plate work and preparation for painting begun with the application of filler. At the bottom of the vestibule flange where the bellows are fastened the plate has worn very this so new plate was welded in this week.
At the front of the tank a supporting beam has been welded across the tender just behind the tender front. This will keep the tender sides in place when the complete tender front is removed. More work has been done in removing the plate. We had hoped to have a clean cut line at handbrake shelf height but the shelf behind the handbrake has been found to be holed so this will require repair. The last corridor roof section that joins to the tender front received some fitting this week.
Work continued on the installation of the GSMR and AWS/TPWS charging systems, and the protective circuits that will allow its fitting and enable the option of remote charging. The GSMR equipment has been removed from the tender locker and the locker will be refurbished.
The last bushes to go in the top hanger holes in the tender frames are now complete. The pins have been tried in and they go in straight and are a good fit, justifying the work involved in boring through over the previous few weeks. The tender brakeshaft position was adjusted and the position of the end brackets noted. New bushes will be fitted to the end brackets and they will then be bored to give the correct alignment. Material has been obtained for the bushes and they are in the process of being machined.
Also at the rear of the tender frames the steps have been put back on with their associated brackets. One required straightening out as it has received a substantial bend at sometime. Putting these components back has allowed the pipe-fitting team to firm up the arrangement of the water filler pipes that pass from outside of the frames and up through the trailing dragbox.
The sample repair to the tender spring hangers has been satisfactorily completed, so the remaining hangers have now been delivered to contractors for specialist repair. The rectified tender bearing brass has been collected from contractors while the trailing set were delivered to them. The left leading brass has been tried in its axlebox and after a little dressing of corners gave the correct movement in the axlebox. The right axlebox brass is being scraped to its journal.
Scraping bearings can be time consuming and we can reduce this time the closer we can get the initial machining to the final profile we want. The risk is if we machine too much material there will not be sufficient to scrape away. In discussions with our contractors they have suggested that we make a profile plate to suit the individual journals which they can then use to make a tool for finishing the bearing while on the machine, still allowing a scraping allowance, but much closer to the final profile than using a single radius tool. A start was made on making the profile plates this week.
All the tender hornstays are now reamed and are ready for new bolts.
The blast pipe casting was moved last week in to a bit of space so that it can be worked on. This week the removal of the blast pipe tops was completed. These will be replaced. Work will continue of recovering the fastening holes in the blastpipe and removing the carbon inside.
A start was made in fitting the new slidebar bolting this week, it is planned to make a blank to enable us to size the bolt hole diameters accurately without the need to machine and fit each bolt individually. This should reduce the amount of machine time needed for finishing the bolts.
Work on the middle crankpin continued this week, making a start on restoring the fillet curve between the crankpin parallel section and the where the pin enters the crank web. Meanwhile the in-house NDT of the middle connecting rod has been completed with examination of the strap. The strap will now be subjected to third party specialist examination.
13 May 2019
At York the tender continues to consume most of our manpower. The end is now in sight for the rear of the tank. The last of the plate work has been put in the top of the rear tank, and in the bottom of the vestibule. A new vestibule floor plate has been cut to shape and ground to remove the flame cut edge. The plate has now been drilled to eventually fasten through the vestibule and rear dragbox.
At the front of the tank the first section of steel has been cut out in preparation for the renewal of the steelwork above handbrake shelf level. The tank has been measured accurately including the location of all the holes and details so these can be put back in the correct location. A review of the layout is being carried out regarding the location and storage of the AWS/TPWS batteries and conduit runs.
The tender brake overhaul continues with the rear top hanger holes in the frames and rear dragbox now been bored out. The tender brake hangers have been re-bushed where required, and tested for defects. Their fit on the brake blocks has also been checked. The hangers have been tried in position and are now being painted. The brake hanger tie bars have been tested for defects.
The tender brake shaft has now been tried in place to check the fit of the bearings on the frames and the movement of the shaft. Some work is required on the positioning of the bearings and then a decision will be made on bearing renewal.
Inside the tender corridor work has continued on needle gunning the plate work to assess its condition. It is very noisy so it has progressed slowly as nobody wants to hear it all day. The condition of the plate varies but hopefully hole free.
The piping in the tender frames steadily grows. The piping around the front of the frames where it has to clear the vacuum cylinders, brakegear, axles and water valves and pipes, has now been installed. At the rear of the frames a template has been fitted over the rear dragbox locating the drains from the tender tank top that are used for the hydrant filler pipes and it is planned to use them for the air pipe runs. The vacuum reservoir cylinder has also been refitted to enable the installation of the water filler pipes, vacuum train pipe and steam heat pipe. The vacuum train pipe is now installed to the rear bufferbeam.
The tender springs are with contractors for refurbishment, meanwhile work progresses on the spring gear. A repair procedure has been agreed with our VAB for the spring hangers and these are now being worked though. Some of the bottom plates on the rubber springs were found to be fractured and new plates have been purchased, drilled and finished at York. Studs are used to lock the position of the nut that the plates are against and new are being made.
Work progresses on the reaming of the tender hornstays in preparation for new bolting with the right hand now completed.
At contractors the new patterns for the cast iron steam pipes for the smokebox are now complete and casting should commence soon. The side-rod bush bronze has been machined and the moulds for the white-metalling are now being made. The first two tender axlebox brasses have been white-metalled and returned to York for fitting. The new outside motion pins have now been returned from the heat treatment contractors and are being finished machined.
Though the tender is the main focus of the Engineering Team, work continues on the loco. Work has continued on the lubrication pipes to the atomisers. The atomisers are stood on temporary brackets as they are normally mounted on the side of the smokebox below the streamlining. The fittings on the pipe ends will require renewal, we have spares in stock. Some other outstanding pipework has been completed at the tender end.
The leading and trailing coupled wheels now have their oil trays fitted complete with new oiler pads and felt pads for oiling the inner face of the wheels. The dust guards have also been fitted after receiving refurbishment work to tidy them up. Though we still need to fit the dust seal ropes. They were previously felt, however hard engineering felt is amazingly expensive. The spring pin retaining boxes have now had all new cotters made, as have the coupled wheel horn adjusters.
The finishing of the parallel section of the middle crankpin has now been completed. This leaves the end radius to return to the correct curved profile. To achieve this a gauge has been made reproducing the correct radius. It has been tried on and has shown very good contact on the journal showing what a good job has been done. It also shows the work that needs to be done on the end radius. The return cranks mounted on the outside crankpins are currently being fitted. A jig is planned to ensure their correct positioning on the new crankpin ends, and the refurbishment work for the cranks to restore wear has been planned.
Meanwhile the middle connecting rod is in the process of assessment. The little end and rod has been examined for defects and the big end has been measured for roundness, essential for a good fit and support for the bearing. The strap position being adjusted with shim to find the best location to provide roundness.
The valve guide castings are being examined with one found to be cracked. A pattern has been loaned to enable new to be cast and quotes are presently being sought.
The bottom three front lamp irons have been refurbished removing the very worn uprights which gave a loose fit to the lamps. This job was started by the junior volunteers of the 007 Gang who checked the profile on Mallard's and our relatively unworn top lamp iron. New were then milled to the shape required by an Engineering Team volunteer. They were finally polished and bolted in place by one of the JVs involved in the originally specifying of the profiles.
New shims have been completed for the lower slidebars and are now fitted. The gaps have been remeasured and approval of the CME has been received, so no further adjustment is required. A survey of the current state of the slidebar bolts has been completed and the new bolting specified received from suppliers manufactured from our drawings, though there's a lot of work in fitting them. The holes in the crossheads for the union link have been measured and it is planned to do some work to them to return them to true roundness. One is already bushed and the bush was taken out.
The final assembly of the safety valves didn't quite go according to plan. It was noticed that the top cap on one of the valves, manufactured at some time during preservation could foul the vanes in the top housing, so the cap was machined to reproduce the internal profile of the original top cap in our other safety valve. The new springs received a little work to their end coils to get them to stand a little squarer, and the valves were finally assembled and are now with the boiler.
The snifting valve was retrieved from store and dismantled. The bronze valve inside has seen considerable wear and has a section broken off. It will require replacement.
At Llangollen a landmark was reached when the boiler successfully passed its hydraulic test with the boiler insurers and VAB in attendance. The boiler will now be steam tested and the superheater fitted. While work on the coach bodywork repairs is well under way. More work has been done at the ends and renewing corroded sections under the floor. Some plate has been renewed around the windows.
15 April 2019
The AWS battery box lid has suffered from corrosion between the lower mounting strap and the surface of the lid. The strap was removed and the corrosion cleaned out. The lid was not flat so was carefully pressed straight and sections of steel tacked to the back of the lid to keep it straight. It was taken to contractors this week for weld repair and for the strap to be put back on.
The coupling rod bush drawings have now come back from the CME's office approved. The order has now been placed with contractors for machining and whitemetalling. The castings, some of which have seen some pre-machining by our volunteers, were taken to the subcontractors this week.
The tender vestibule top arch has now been drilled for the handrail that curves round the arch. The knobs look like they can be reused but the rail is corroded through in places and will be renewed. The arch has been painted and bolted in for the last time. The boiler making team have now moved on to the renewal of the rear top left platework. A new tender floor support bracket has been welded in to the front of the tender tank.
The pipes from the cylinder mechanical lubricator, run to the atomisers. The atomisers are mounted on brackets on the smokebox, which is not yet in place so some brackets have been made to mount the atomisers in their approximate position, and this week the pipes were run in. There is work to do on supporting some of the pipework and at the atomisers new ends will be required for the pipes. Meanwhile on the tender, the routing of the air pipes continues.
The tender brake hangers are now all reamed for their pins and drilled for grease nipples. The new bottom pin was finished. Work continues on boring the holes in the tender frames to mount the trailing hangers. The right side is now completed. The old oil holes in some of the tender brake hangers have been plug welded and dressed. The hangers have been cleaned of all the swarf from reaming and drilling.
The new plates for the bottom of the tender spring hangers were collected from the suppliers this week. The flame cut edges were dressed with a grinder. The tender frames back to back have been remeasured, now that we have tight hornstays and these dimensions will be used to specify the rest of the axlebox bearings. The leading set are in the process of being metalled at contractors.
Work continues on overhauling the cylinder relief valves, with five of the six now completed. The right leading crankpin cap has now been fitted to the tolerances shown on the BR drawing. The left hand cap needs a few thou taking off.
The middle crankpin has seen further work with the first lap of filing completed and polished to remove file marks. Further filing followed careful measurement. After this is polished and finally checked, work will begin on finishing the corner radii.
The tender rear coupling hook has now been put in the dragbox for the last time. The safety valves have been assembled with their new springs and more NDT work has been carried out on the valve guides.
Most of the new lower slidebar shims have been cut out and drilled and have been finished to size on the Churchill surface grinder. The existing ones that had sufficient thickness have been ground to size. Work continues on specifying the replacement slidebar bolts.
8 April 2019
The boiler is now turned upright after completion of the flues and small tubes. The last of the firebox stays which were not accessible on the outside of the boiler when on its side have now been finished. One of the last jobs was finishing the belly door face on the boiler and getting a new seal. The door is now in place and water has been put in the boiler. At the moment only the water legs of the firebox have been filled so that the new sections of firebox wrapper, foundation ring and new staying can be closely examined for any leaks.
At York the safety valves have been lapped in after the valve faces were skimmed. The last step is now to fit the springs.
The tender springs have now been delivered to contractors for overhaul, and the firebox grate components taken to Llangollen from Grosmont and York. The tender spring gear components are now being refurbished with the first two hanger bolts with contractors for repair. A detailed repair procedure has been agreed with them and the first two will be subject to third party NDT. The bottom plates from the rubber springs on the end of the hanger bolts have now been di-pen inspected. One was broken in two when removed from the tender and another has now been found to be cracked. A total of eight new plates are now on order and all suspect plates will be renewed.
The spacer to get the rear coupling height correct has now been finished and an additional wearing plate has been screwed to the top. The buckeye coupling has been adjusted and should now measure correctly when in the open position. A representative of the UK manufacturers of the buckeye coupling is due to call by over the next few weeks and will gauge the coupling.
The tender brake hanger overhaul continues. There is only one of the lower hanger bushed holes to ream and a new pin has been machined. The fitting of grease nipples is planned for the hangers so they have been drilled and tapped, and nipples bought ready for fitting. The tie rods that go between the lower ends of the brake hangers have been cleaned and descaled and are now ready for inspection.
The rearmost tender top brake hanger holes are worn and no longer provide correct alignment so it was decided that they should be bored out along the same centre. The first hole, in the rear dragbox has been successfully bored. The jig now needs re-positioning to bore the corresponding frame hole using a guide in the repaired hole in the dragbox.
Work continues around the rear of the tender on the platework. The tender vestibule top arch has been fitted, not without a struggle. The arch piece was pulled down on to the vestibule top and was welded to its flanges. When trial fitted it was found difficult to refit. The arch with flanges wants to come straight down to slot in to the space between the vestibule end and the tender back. However there is beading along the top of the tender projecting in to the gap needed to lower the arch.
The cylinder relief valve overhaul continues with various gadgets being made to ensure accurate lapping of the sealing faces. Most have now been pressure tested successfully, but will require checking with a calibrated gauge to ensure they lift at the correct pressure.
The coupled axlebox oil trays have now been fitted to the leading and trailing axleboxes. Meanwhile the springs were put up. One spring didn't seem to hang right and was very high at one end. When examined it appears that the hole in the spring buckle is out of position, and this will have to be rectified. However it us some extra practice in handling the springs. One reassuring finding was that the repair to the leading right spring hanger bracket did not cause any additional difficulty in getting its spring in place.
Other activities around the coupled wheelset include the adjustment of the wedges using long feelers to ensure the gaps are correct for the axleboxes. New cotters are now being fitted to lock the position of the wedge adjusters, meanwhile final torquing and pinning continues for the vertical hornstay bolts. The driving axleboxes are now scraped to their journals and attention has now turned to the refurbishment of the inside crankpin.
Work on specifying the coupling rod bushes is complete and component drawings have been produced. This has involved measuring the current worn positions of the driving crankpin face against the wheel and relating this to the leading and trailing crankpins to ensure we maintain the clearances required by the coupling rods. The holes in the rods have also been carefully measured. These aren't plain bores but have tapered or stepped recesses to locate the bushes when pressed in. Correct location is required to ensure the right amount of the bush projects from each side of the rod.
The lower slidebar fitting is now on the final stretch with the shims specified and they now being made.
The installation of pipework continues. More work has been done on the tender and a lot of thought put in to how to improve pipe runs through the frames and to the tender top air tanks. Meanwhile the pipework around the DV2 valve in the loco frames is complete and the mechanical lubrication runs to the front of the saddle is now progressing. As the upper slidebars are now fitted the lubrication runs to these has begun. The mechanical lubricator drive mechanism components have been examined and are now being refurbished.