The Sir Nigel Gresley Locomotive Trust LtdSubscribe to 60007

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OVERHAUL 2015 - 2018

All the overhaul photos may be found here.



Sir Nigel Gresley is now out of traffic for overhaul. This will probably take three years and cost about £750,000. If you would like to make a donation towards this overhaul please click on one of the the donate buttons.


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Notes from information supplied by Darrin Crone, Locomotive Engineer.

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From April 2017.

24 April 2017

With the footplate riveting finished, paint has now been applied around the riveted areas. This has enabled the 2 large oil boxes to the rear of the saddle casting to be fitted on freshly painted brackets. These were earlier retried from store and given a finish clean and some minor attention to the connection threads.

Earlier in the week all the axlebox mechanical lubricator copper piping was retrieved from store. The pipework, as usual, was given a further clean through and is now going through the process of inspection, repair and annealing. The Mechanical lubricator has now been returned from overhaul, which has been carried out by our CME.

The brackets that support the unions between the flexi pipes that run from the axlebox lubricator copper pipes, have been stripped down and are currently being painted. I was going to fit them to the loco and have them painted in-situ but the painting team vetoed that decision as a better job can be done on the bench. The unions themselves have received cleaning and repairs to some damaged threads.

The trial fitting of the leading right hand combined spring and brake bracket has required some dimensional investigation to ensure that when left and right brakeshaft bearings are placed on the same centre line that the right hand bracket positions the centre of the spring under the centre of the axlebox. In addition we have to ensure that there is sufficient clearance for the spring to move while in traffic. To achieve the common bearing centre line still requires the removal of some material from the trailing edge of the bracket for final fitting as when trialed it was very near the hornstay.

Work on the manifold assembly continued this week with attention turning to the manifold casting itself. All the valves have now been refurbished except for the manifold shut off valve which is an integral part of the manifold casting. Work started by removing wasted studs, then cleaning and carefully abrasive blasting the surface. This will allow a detailed inspection of the surface.

The bogie frames inspection was completed this week, and no time was wasted by the Painting Team as by the end of the week undercoat was being applied. We are concentrating on painting the underside of the bogie before we turn it back up the right way and these areas cease to be easily accessible. The side control springs, to be fitted before turning the bogie frames, were finished painted this week. The spring cups, spacers and other parts were painted some time go.

The bogie axleboxes have been closely examined and measured by our CME, however this week to ensure their soundness we di-pen inspected the flanges of the axleboxes to ensure there are no cracks. All are defect free.

Cylinder and saddle bolt boring continued this week with the boring of the first of the really challenging holes. This hole was bored through and partially reamed before work ended this week. There are only two holes left and these are the really - really challenging ones. At the trailing end of the saddle the last of the life expired bolts that fasten the saddle to the middle cylinder casting were removed this week. The holes were then cleaned out to remove corrosion.

Work began this week on the Cartazzi refurbishment with paint being removed from the wheelset axle. A bit of a challenge with it still in position the Engineering Team coped very well, as to be expected. The Team also continued the examination of the vacuum cylinders with the piston rods examined for wear and distortion. The loco drawbar gear has been removed and measured over the last few weeks and work continued this week on these parts with them receiving a good clean before they receive their crack detection examinations.

The inside of the up-turned bogie frames are now receiving undercoat now that the frames have been proved defect free. 19 April 2017
Photograph: Darrin Crone.

Inside up-turned bogie frames

The bogie axleboxes have been dye penetrant inspected to ensure there is no cracking in the corners of the flanges that control the lateral position of the axlebox and wheelset. 19 April 2017
Photograph: Darrin Crone.

The bogie axleboxes

The manifold that normally sits inside the cab on top of the firebox and supplies steam to various systems on the locomotive under the control of the crew. The flanges are normally coupled to valves. The manifold has been cleaned and some of the damaged mounting studs have been removed and will be replaced with new. 20 April 2017
Photograph: Darrin Crone.

The manifold

The piston from one of the vacuum cylinders sees daylight infrequently. Dated 1953 it looks to be in as new condition. 20 April 2017
Photograph: Darrin Crone.

A vacuum cylinder piston

The bogie frames by the end of the week covered in undercoat. This will be glossed next but painting of the outside frames and upper surfaces will be completed when the frames are returned to their right way up. This is a view from the front of the bogie. The brackets on the front of the bogie support a beam on which is mounted the AWS receiver. 20 April 2017
Photograph: Darrin Crone.

The bogie frames in undercoat

A view of the painting bench with the bogie side control springs in bright red, ready to refit in the bogie. In the foreground one of the oil boxes which has received it's last attention before fitting to the loco. 20 April 2017
Photograph: Darrin Crone.

Bogie side control springs

The boring of the front top cylinder flanges continued this week with the uppermost in the photograph just bored through. This is the right hand side. Just one more to do each side then this marathon is over. 20 April 2017
Photograph: Darrin Crone.

The front top cylinder flanges

The large oil boxes located just to the rear of the saddle were refitted this week over the recently fitted footplate rivets and newly painted footplating. 21 April 2017
Photograph: Andy Barwick.

The large oil boxes

16 April 2017

New linings were fitted to the reverser clutch this week. This involved heating them in an oven to make them pliable then bending them to the correct curve to fit in the recesses in the clutch. The linings are screwed in place and the screws were replaced as it apears some of the old screws were not of the correct thread type so were found to be damaged upon removal. The complete clutch was then assembled on the bench and the reverser shaft sheaves were used to test the fit. The linings certainly get a good grip.

The overhaul of boiler fittings and valves continued this week with the blower valve striped and inspected. The valve seat lapping was completed and the valve repacked and reassembled. The valve is now ready for reuse. Work has now started on the overhaul of the manifold valves. Some see very little use in traffic, such as the shut off valve for the boiler pressure gauge, however others, such as the steam heat valve don't live such a quiet life and the wear is considerable. Upon inspection of this valve it apears to be life expired and will require replacement.

The new stud for the displaced thrust in the right driving axlebox was made and fitted this week. All the axleboxes are now ready for re-metaling, though we still await the dimensions of the finished journals.

The painters have been busy again with the first primer coats being applied to the inside of the saddle, after a final coat of the needle gun. The Painting Team have been itching to get it painted for weeks.

Inspection of the bogie continued this week with the examination of the front and rear stretchers and all around the horns. The outside central sections of the frame plates are all that remains to be done. By the end of the week the first coat of primer was applied to the underside.

The overhaul of the vacuum brake cylinders began this week with their dismantling. There are three in total, two smaller ones mounted side by side toward the front of the loco with the larger one mounted further back between the frames. The brake hangers and cross beams were mounted on the loco by the 007 Gang of junior volunteers last week, and this week the inspection of these components began.

The outside cylinder bolt hole refurbishment continued this week. Only three remain to be done, all others having now being bored and finish reamed. The jig used so far to ensure accurate alignment will now require modification to access the remaining holes.

Inspection and assessment of the loco draw gear continued this week with the removal of the tender eyebolt and its rubber spring. The eyebolt passes through the front tender dragbox and the intermediate main drawbar is pinned in to it. This has now been measured and its current dimensions will be compared to drawing and permissible wear limits. It can then be decided if it requires any repairs or replacement. Measurement of the front drawhook shows it to be fit for further use, in fact it is surprising how little wear there is on the hook, however until the last ten years, it spent most of its time on the mainline so the front hook probably didn't get much use.

The right hand leading combined brake shaft and spring bracket returned from repair this week. It was trial fitted to the frames on Saturday. Measurements were taken of the trial position and compared to the position of the existing left hand side. As to be expected from a hand built 1930s locomotive that has seen a long active life things are not exactly to drawing so a certain amount of fitting is still required before finally locating the bracket. A cutter has been obtained and a set up devised that will accurately drill mounting holes in the bracket to match the holes already in the frames.

The final rivets were put in to the right hand footplating this week. The last ones went into the slide bar bracket. Attention then turned to putting in the last rivet in the left hand side footplate bracket. Shortly after completing the riveting of the outside slidebar brackets the footplating received its first coats of primer in preparation of refitting the oilbox brackets that sit on the footplate in this area.

The assembled reverser vacuum clutch with new linings in place tested with the reverser shaft sheaves in place. 12 April 2017
Photograph: Darrin Crone.

Reverser vacuum clutch

The upturned bogie frames have been extensively tested to ensure they are free from damage and defects. 12 April 2017
Photograph: Darrin Crone.

Upturned bogie frames

A tiny detail, but requiring making from scratch, a new locating stud has been fitted to the thrust insert in the right driving axlebox. 13 April 2017
Photograph: Darrin Crone.

New locating stud

Not mentioned in the report, the plates at the back of the bufferhead that compress the smaller rubber springs an the back of the buffer assembly have been skimmed to remove deformation from decades of use. 15 April 2017
Photograph: Darrin Crone.

Back of the bufferhead

The tender eyebolt mentioned in this week's report has been examined. 15 April 2017
Photograph: Darrin Crone.

Tender eyebolt

The loco vacuum brake cylinder overhaul has begun. The larger cylinder nearest the camera is mounted between the driving and trailing coupled wheels and the 2 smaller cylinders are mounted in front of the leading coupled wheels. They are linked on the loco by brakegear that combines their brake force. 15 April 2017
Photograph: Darrin Crone.

Loco vacuum brake cylinder

The refurbished combined spring and brake shaft bracket trial fitted to the frames. 15 April 2017
Photograph: Richard Swales.

Refurbished bracket

9 April 2017

The installation of the coupled wheel horn lubricating pipes was completed this week. The trailing set were fitted last week. The remaining mechanical lubricator bleed valves were also cleaned, inspected and refitted this week. While between the frames the combined control reservoir and the air pump exhaust silencer box were also refitted. The tee that splits the steam supply to the steam sands to both sides of the loco has also been fitted.

The overhaul of boiler fittings and valves continued this week with the retrieval from store of the blower valve and the valve that was used to isolate the steam chest pressure signal to the exhaust steam injector, when that was fitted, but is now used to isolate the steam chest pressure gauge. The blower valve was dismantled and the valve was skimmed to return it to its correct profile. The seat was then ground but there are still a couple of marks that will have to be removed. The steam chest isolation valve does not see much operation so was in good condition. When lapped with a little fine abrasive paste it almost immediately showed continuous contact.

The last remaining corners behind the front bufferbeam were needle gunned and primed this week, leaving just the area around the Cartazzi and the bogie stretcher to do. Alan had previously finished stripping and descaling the underside of the bogie and this week its detailed inspection began. The bogie centre casting was di-pen inspected this week. The bogie frame rivets and fitted bolts were also examined and all have proved to be tight.

This week representatives of the Engineering Team visited Llangollen to see progress with the boiler. As reported previously the left hand side out wrapper sheet has be welded in place and work continues on its fitting to the outer door plate and foundation ring. Work has begun on the removal of the combustion chamber stays on both sides, and there is a plasma cutter on site and it is now being used for the removal of the copper tubeplate. The new copper tubeplate being supplied by Crewe is now being machined so we are expecting completion of this in the next couple of weeks.

The inspection and measurement of the loco drawgear continued this week with the front draw hook and coupling shackle. The tender "eyebolt" that the intermediate draw bar is pinned into is the only remaining item that requires inspection but first we have to find a spanner to fit the large nut that fastens it in place.

We had another riveting session on Friday and the team got on very well. Unfortunately the old rivets on the leading left hand footplate bracket had come loose over last weekend, due to the clamping of the new rivets we put in. So these had to be removed and new rivets put in. By the end of the day all the left hand footplating had been riveted, except for one hole. When inspected the next day all were tight. We are still trying to work out how to get a rivet in to this last hole.

On Saturday the 007 Gang, our Junior Volunteers, retrieved the brake hangers and beams from store and refitted them to the loco. They did very well to refit these heavy parts on the loco. They have been refitted as we plan to measure their positions prior to refurbishment. After they completed this task they then started to descale under the tender front dragbox.

The boring and reaming of the outside cylinder holes is going well with more that half the holes bored and approximately half the holes finish reamed. A number of bolts are life expired where the saddle casting and middle cylinder are fastened together. On Saturday we began the process of replacement by drilling and then punching out the first two.

A view of the original copper tubeplate. The combustion chamber side stays have had their heads removed and are being drilled out.
Photograph: Trevor Camp/SNGLT.

The original copper tubeplate

The rear top side corner stays are also being renewed at this overhaul. This picture show the right hand side.
Photograph: Trevor Camp/SNGLT.

The rear top side corner stays

The partially assembled air pump awaits the return of the repaired steam cylinder at the back left of the bench. Not mentioned in the report, new stainless steel springs were fitted to the air pump non return valves this week. The primed components are parts of the reverser vacuum clutch.
Photograph: Peter Brackstone.

The partially assembled air pump

The refitted air pump exhaust box sits on the steam sand box to the right of the picture. The taped up fitting on the horizontal stretcher is the tee to the steam sands supply.
Photograph: Peter Brackstone.

Refitted air pump exhaust box

The bogie centre has been thoroughly cleaned and is being inspected by Bob Shearman.
Photograph: Darrin Crone.

The bogie centre cleaned

A corner section of the bogie centre casting. The bogie is upside down so the bottom of the bogie is at the top of the picture and the rivet heads secure the casting to the left hand bogie frame plate. It can be seen that the corners have been extended to give the frame plate extra support. Existing rivet holes were welded up and new rivets put in when the corners were extended. The new sections are marked on their edge 2553.
Photograph: Darrin Crone.

Corner section bogie centre

The horn lubrication pipes are now all installed.
Photograph: Darrin Crone.

The horn lubrication pipes

Two new rivets put in the left hand slide bar bracket. The corner hole apears never to have been riveted as the footplating above has never been drilled through.
Photograph: Darrin Crone.

Two new rivets

The brake hangers and beams have been fitted so that they can be dimensionally checked prior to refurbishment.
Photograph: Darrin Crone.

The brake hangers and beams

2 April 2017

The brass oil boxes for lubricating the coupled wheel horns were fitted last week and the oil pipes were retrieved from store and cleaned. This week they were annealed and then the set for the trailing set of horns fitted. The remainder are ready to install. Also this week the bleed valves that are in the lubricating lines from the mechanical lubricator to the coupled wheel under keeps were were also retrieved from store. They were dismantled and cleaned out and all apear in good condition. A start was made on fitting them on their brackets at the top of the frames.

The combined control reservoir that, with the DV2 valve, allows vacuum brake application to be controlled when the loco is operating an air braked train was retrieved from store this week. It was pressure tested and examined and will be suitable for further use. By the end of the week it had been repainted and is now ready for refitting. A lot of time was spent last week painting the numerous individual small brackets between the frames that clamp pipework in position. Fitting the lubrication clips that are fastened under the splasher frame bracket bolts was completed this week.

The coupled wheel axleboxes have bronze thrusts on the horizontal diameters. These are kept in place by headless screws, however one screw is missing and the thrust has moved slightly. This was carefully repositioned and the thread cleaned up. A new screw will be made and fitted.

The inspection of the intermediate drawgear continued this week, with the main drawbar being measured and compared to the LNER/BR drawing and the permissible wear allowances. The loco drawbar pins, main and safety link, also received this attention.

The reassembly of the air pump started this week. It cannot be completed yet as we are waiting for the return of the steam cylinder and new springs for the non-return valves. The Air Pump refurbishment team have now turned their attention to the reversing shaft vacuum clutch. This clamps tight to the reversing shaft to secure the valve gear cut off position. The clutch has now been stripped and inspected. The clutch operates through the application of vacuum on a rubber diaphragm and this diaphragm will be replaced. The grip on the shaft is achieved with brake linings, and these also require replacement. One interesting find was the marking on the clutch of 2510 and 15, both numbers carried by A4 60015 Quicksilver.

The needle gunning of the upturned bogie was completed this week. The bottom of the bogie structure can now be di-pen NDT examined.

Last week the hole for a new fitted bolt was prepared on the right leading coupled wheel horn and this week the new bolt was machined and fitted. Work on the repair of the cylinder flange holes continued with some holes bored and another completed by reaming through.

We finally got back on to riveting this week with both front footplate sections being riveted on to the brackets over the 2 to 1 link cut outs. The right hand side required four out of five rivets replacing whereas the left required two replacing.

On Friday the combined spring and brake bracket was receiving its last attention at the works of K D Flavell with the groove for the Spenser spring box being cut. At Buckfastleigh all the coupled wheel tyres have now been finished profiled and journals and thrust faces are now being measured and skimmed where required.

The combined control reservoir was manufactured by BR at Crewe in 1972 and feels like it is made from armour plate. 29 March 2017
Photograph: Darrin Crone.

Combined control reservoir

The trailing pair of horn lubricating brass oil boxes were fitted last week. This week the oil pipes were installed. At the top of the frames near the oil boxes are small bleed valves on brackets that are in the lubrication lines from the mechanical lubricators to axlebox underkeeps. 30 March 2017
Photograph: Darrin Crone.

Horn lubricating brass oil boxes

The outer strap of the vacuum clutch bears marking 15, 2510 and 7, with 15 and 2510 struck through. 30 March 2017
Photograph: Darrin Crone.

Outer strap of vacuum clutch

The complete vacuum clutch and the split sheave that clamps on to the reversing shaft. The gap between the sheeve and the outer strap of the vacuum clutch housed a brake lining removed in the photo. The clutch is mounted horizontally on the face that it sits on the bench in the photo. 30 March 2017
Photograph: Darrin Crone.

Vacuum clutch & split sheave

The new left hand outer wrapper side sheet is now being installed. 30 March 2017
Photograph: Peter Brackstone.

New outer wrapper side sheet

The whistle was refitted this week for sounding on the 50th anniversary of the loco's first run in preservation. 31 March 2017
Photograph: Peter Brackstone.

Whistle refitted

New rivets fitted to the front right footplate bracket. 1 April 2017
Photograph: Darrin Crone.

New rivets fitted
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