Engineering Report - November 2022

Work on The Unknown Warrior has continued over the period since the last report. It is very pleasing to be able to report physical progress towards the re-assembly of the chassis. Also, the large amount of effort that has been undertaken on planning and agreeing the work required on all parts to obtain confirmation of the material specifications is starting to show positive results.

Work is also progressing on compiling a history of the design of the Patriot class locomotives in service and recording changes and modifications made during the service life of the class. The work is being headed by new Engineering Team member Bruce Murray who will expand on this and other related work on separate articles in this and subsequent Warriors. The recent acquisition of the Engine History Cards for all members of the class and a small number of Engine Record Cards from the late 1940’2 and 1950’s has greatly helped this work. It is possible that the Engine Record Cards for the class member we do not have may not have survived, although further searches are being made. We thank our friends in the Railway Travel & Correspondence Society for providing this information.

Work continues on the refurbishment of the Main Frame Assembly.  Recent activity has seen the Dragbox and Boiler Expansion Brackets removed to enable the Frame Plates to be shot blasted and undertake any welding repairs to incorrectly drilled holes as explained in the previous report. At present the alignment of the Fame structure is being maintained by the 3 rear Frame Stretchers. The plan is for these to remain n place until all rectification work on the front section is complete and the Forward Stretchers are replaced and riveted into position. These will then maintain the alignment whilst the 3 rear Stretchers are removed for the Frame Plate rectification to be completed on the rear section.

The order for a new Dragbox has been placed on Tyseley Locomotive Works. The original Dragbox has been found to be both slightly out of square and also has been machined unequally on the faces that mate up to the Frame Plates. We also have no welding documentation covering the construction. It could be possible to have the welds tested, but the cost in both monetary terms and time to agree the process and then undertake the testing was considerably more than obtaining a new Dragbox which will come complete with all the required documentation.

Work on the testing of components to verify material specification has become bogged down while sorting out the details of the work. All parts are still waiting to be dispatched as soon as the contractor is ready to receive them.


Machining of motion fittings continues as time allows.


Welding Repair

The repair work on the Outside Cylinders is underway following the delayed delivery of the material required for the Valve Guide Bars.

A view into the Valve Chest of one of the Outside Cylinders showing the new Port Bars in position. Photo by PRCLT


The Inside Cylinder following shotblasting. Photo by Pete Sikes.

Driving Wheels

Work continues at William Cook Cast Products on our 6 Driving Wheels. They are now in the process of proof machining. Proof machining is a first stage machining of the raw castings to prove that they are of good quality with no visible flaws or inclusions in the material. In the case of these wheels it was decided that we would leave 0.2” of material on all machined faces for removal by South Devon Engineering on the final machining operations prior to assembly.

The Proof Machining drawing produced for our Driving Wheel castings. LMS Patriot Co Ltd

We expect they will be ready for dispatch to the South Devon Railway for assembly during the next few weeks. We were asked to supply a new machining drawing for this work which took longer to produce due to our Chief Engineer recovering from an operation on his ear which left him with balance issues and being unable to sit at the computer for extended periods.  I am pleased to report things are now almost back to pre-operation levels.

We then produced the three machining drawings for the wheels of each driving axle. These have been finalised and sent off for approval.

The Final Machining drawing produced for the Centre Driving Wheels. LMS Patriot Co Ltd

We have been trying to arrange a visit to South Devon Railway to discuss the assembly of the 3 Driving Wheelsets, but staffing availability due to a number of reasons including Covid, my own health issues and Simon Scott’s availability have delayed plans. We hope this will now take place towards the end of November.

Meanwhile, at West Shed, work to recover the Crank Pins and Balance Weights and from the original wheels is almost complete. These parts will be reused on the replacement Wheelsets.

The replacement Trailing Axle has been completed in South Africa and is currently in transit to the UK.


Work continues on the re-work of the Bogie as time permits.


HBSS continue working on our boiler to an agreed program which fits within our financial budget and is


A similar planned schedule of work applies at Leaky Finder for the Tender Chassis. The current focus is the

Tender Tank Design

No progress since last report.

The LMS-Patriot Company Ltd. • Civic Centre, Riverside, Stafford, ST16 3AQ
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