Engineering Update - February 2021


Work on The Unknown Warrior has continued at a limited pace since the last report.

Workers need a good mug of tea!. Photo by PRCLT

The PRCLT trust engineers continued working in isolation from the beginning of Lockdown 2 until the workshop shut down for an extended Xmas break on 11th December. The main focus on work at present is the planned winter maintenance of 6233 Duchess of Sutherland, to ensure the loco is ready for the resumption of main line activity in the early summer. Simon Scott is still devoting one day a week to physical work on 5551, so actual progress is being maintained. In addition, Simon is providing technical assistance and liaison with Ian Riley & Sons and Ricardo Rail in relation to both current and future work.

Chassis & Motion

Work on the locomotive chassis at West Shed continues.

Valve Chest Drain Mountings after machining. Photo by PRCLT

Work has been completed on machining the Drain Cock Mountings for all 3 cylinders, although a couple of awkward to get at holes need to be tapped in the Outside Cylinders for these to be mounted on. We like to make life interesting for Simon, so he does not get bored!

The Inside Drain Cocks have now been mounted to check the operating of the Drain Cock Gear.

The Drain Cocks and Operating Gear under the Inside Cylinder. Photo by PRCLT

The Main Reverser Shafts has been trial fitted into the chassis to check for alignment and clearances. This shaft is mounted in four bronze bearing lined trunnions, the outer pair are mounted outside the frames on the Rear Motion Girder Bracket and the inner pair mounted to the inside of the Main Frames. 

The Main Reverser Shaft and LH Inner Trunion. Photo by PRCLT

As mentioned in the last report, we will have to submit the manufacturing process used to Ricardo Rail for approval as no paperwork can be found to support the previous approval from our former approvals body. There are also some concerns about some unexplained flexibility in the Outer Arms where the slot has been machined for the Radius Rod and Die Block?

A CAD image showing the Reverser Shafts. The Main Reverser Shaft (in light blue) controls the valve gear for the Outside cylinders. The Intermediate Reverser Shaft (in green) controls the valve gear for the Inside cylinder. The Intermediate Reach Rod (in yellow) transfers movement of the main shaft forward to the Intermediate shaft. Image by Kevin West

The Main Reverser Shaft being installed in the chassis. The two arms to the top of the picture are for the balance weights. Photo by PRCLT

The Main Reverser Shaft after installation in the chassis. The LH Radius Rod is seen in position in the slot of the Reverser Shaft Arm. The Outer Trunnion can just be seen to the right end of the Arm. Photo by PRCLT

The Intermediate Reach Rod was delivered to West Shed on 3rd February, having been in store at CMS Cepcor where it was machined. This has now been installed along with the Intermediate Reverser Shaft to  allow the operation of both main and intermediate reverser shafts.

A view looking forward showing The Intermediate Reach Rod installed onto the Main Reverser Shaft. Photo by PRCLT

2 views of the front end of the Intermediate Reach Rod about to be assembled into the Intermediate Reverser Shaft. Photo by PRCLT

The assessment of the motion repairs undertaken at Llangollen is also planned to begin shortly. Progress had not been possible due to the unavailability of the press that PRCLT normally use to push the bearings out of the rods. This has been solved by the purchase by PRCLT of a 150 ton hydraulic press, which enables this type of work to be completed in house, without relying on the availability of someone else’s press. Several pieces of thick wall tube large enough to press the bearing into have been ordered and once they arrive this work can be progressed. We have an on-line meeting with Llangollen booked for late February, so we hope to have this information to hand by then.

Driving Wheels

Work is progressing well at Ian Riley & Sons, Bury on the correction of the welded repair to 3 of the driving wheels.

The current status as of 4th February is as follows.

Centre Driving Axle.

Both Wheels have been removed from the Axle, the old weld has been removed from the Wheel hub. The hole bore was then and re-welded to the approved method and then machined to the correct size and specification to pressing back onto the Axle.

Trailing Driving Axle.

As described in the last report the Left Trailing Wheel was causing problems as it was impossible to press the wheel off of the axle. The only option was to cut the Axle close to the wheel and the machine the remains of the Axle out of the Wheel hub. This means that a replacement Axle is required and the Right hand Trailing Wheel also had to be removed from the scrap axle, slightly more work than originally anticipated. This has all now been undertaken and the wheel hubs have been cleaned up, re-welded and machined as required, ready for pressing onto the new axle.

This is on order from South Africa, but delivery times have become extended since the order was placed due to Covid-19 restrictions in South Africa. Once received in the UK it will be machined and the 4 wheels will be pressed onto their axles. The final job is to check the tyres still run true by spinning them in the wheel lathe. It may be necessary to give the tyres a skim to ensure they run true, all 3 driving wheel set will have to be done as all wheels must be the same size. Ian Riley has assured us that his new, larger wheel lathe will be up and running for this work, should it be required. The Crank Axle is already at Bury having been sent up with the other set in case this skimming was required.


Work is continuing on the re-work of the Bogie.

The wooden patterns for the Bogie Centre Casting and Bogie Axleboxes have been taken to Premier Patterns and modified in line with the original design, ready for castings to be produced in the coming months.

The CAD 3D modelling has been completed and drawing creation and modification is ongoing.

A design pack outlining the history of the current Bogie and our plan to return to the original design incorporating the modified Front Stretcher as fitted to 46100 Royal Scot, has been created and submitted to Ricardo Rail for their comment and approval before we progress any further. We are waiting for the reply at present.

Once we have approval from Ricardo and all the drawings are complete, we will be able to offer the whole bogie package out to several contractors for quotation to undertake the work. We are hoping that the Bogie will be substantially complete by the turn of the year.

Lubrication System

Good progress continues to be made on the lubrication system, with all pipe runs from the mechanical lubricator on the right hand footplate to the Axleboxes and Horn Guides now complete and clipped in position.

View of the LH Trailing Horn Guides. The guides are at the bottom of the picture with the pipework that supplies the oil to the horn faces clipped to the frames and leading up to the Oil Box. Photo by PRCLT

View of the RH Leading Horn Guides. The lubrication pipes to the horn faces cab be seen fitted into the top of the Horn Guides. The fitting mounted to the frames at the top right is for the flexible oil feed into the axlebox. Photo by PRCLT

At present, 5551 has the correct pattern lubricators borrowed from 46203 Princess Margret Rose in position to enable the pipe runs to be finalised. One job planned for the near future is to strip these lubricators to enable all the parts to be drawn up for manufacture of our own lubricators.


Simon Scott has been busy turning very expensive bronze round and hexagon bar into fittings and bushes for the lubrication system and Valve Rod Bushes.

Completed recently are the Valve Tail Rod Bushes which have been machined and are ready for whitemetalling. The material for the outside Expansion Link bushes is to hand and these are planned to be machined and fitted over the next few weeks.

We have also order a pair of the correct Fowler pattern Safety Valves. These are part of a batch of new valves being manufactured by Locomotive Maintenance Services of Loughborough. Being able to order these as part of a batch give a considerable cost saving over ordering just our pair.

Further work on searching for drawings of the boiler backhead fittings is about to start and contact is to be made with several other loco groups that have locos that use similar type fittings.



In a change from the previous plan to move the boiler from HBSS to West Shed for storage, it is now to stay at HBSS, where an agreed program of continuing progress has been reached. This will see a limited amount of work being undertaken up to the middle of the year, as and when the work schedule at HBSS allows. Beyond that time a further schedule will be negotiated to tie in with completion of the chassis at West Shed to bring the two major assemblies together at the right time.


Leaky Finders are undertaking limited work on the Tender Chassis as staff commitments allow.

Colin Hall and Keith Riches visited Leaky Finders in early December for Ricardo Rail to undertake an inspection of the work completed to date. A comprehensive report has been received, which contains several comments and questions which are to be followed up, but overall indicated general satisfaction with the quality and standard of the work undertaken and the detailed documentation provided by Leaky Finders. 

Below are a few photos provided by Leaky Finder showing recent progress.

Drilling the Tender Front Buffer Beam for the Intermediate Buffer Mountings. Photo by Leaky Finders

Reaming the holes prior to riveting the Intermediate Buffer Mounting in position. Photo by Leaky Finders

The LH Outer Rear Dragbox waiting to be installed between the Main and Inner frame plates. Photo by Leaky Finders

This view shows where the Outer Rear Dragbox is fitted between the Main and Inner frame plates. Photo by Leaky Finders

Leaky Finders engineer, George Bailsdon discussing the work undertaken on the Tender frame with one of the Ricardo Rail inspectors. 8th December 2020.  Photo by Leaky Finders

Inspection of the Rear Dragbox. 8th December 2020.  Photo by Leaky Finders

The Tender frames with protective paintwork completed.  Photo by Leaky Finders


Work continues on locating paperwork.

Approvals and Certification

A huge amount of work is being undertaken regarding obtaining the required documentation to obtain the required approvals and certification for 5551. Colin Hall, Keith Riches and David Tuffin are heading up project teams looking at various aspects including Risk Assessments of components and assemblies, Quality Documents to record manufacture and installation of parts and Modification Recording where we have deviated from the original drawings for any reason, such as use of an alternative material. All this unglamorous work is far removed from the glory of a working 5551, but it totally necessary to achieve our aims of seeing 5551 running on the main line.

Our Chief Engineer has finally finished compiling an Order Register which lists all the purchase orders raised to acquire parts or services for the construction of 5551 since the start of the project back in August 2008. Alongside this register is a Master Parts List which contains details of all the parts of 5551 and all the tasks involved in the manufacture and fitting of these parts, such as making a pattern, casting or machining a part. Each of these tasks can be linked back to a purchase order to record which supplier did the work. From this we know who to contact to request the documentation that covers the task or part. Once again not glamourous work but necessary to obtain the final approvals.

Tender Tank Design

No progress since last report.


The LMS-Patriot Company Ltd. • Civic Centre, Riverside, Stafford, ST16 3AQ
Registered in England & Wales No. 6502248 • Registered Charity No. 1123521
Tel 01785 244156
All content copyright ©2024 The LMS-Patriot Company Ltd.
website by amber