Second pair of coupling rods delivered for Britain’s most powerful steam locomotive
We are extremely pleased to announce that the second pair of machined coupling rods has been delivered to Darlington Locomotive Works only seven years after the launch of the project to build Britain’s most powerful locomotive. The fundraising campaign to raise an initial target of £210,000 needed to pay for the manufacture of the heavy motion has also made good progress, with £175,000 plus Gift Aid already pledged by 175 supporters.
Despite the impact of COVID-19, progress on the construction of our new Gresley class P2 ‘Mikado’ continues to move forward rapidly. The engine has reached the condition where it is recognisably a P2 and the structurally complete tender tank and tender wheelsets are now at Darlington Locomotive Works. Construction and assembly work continues on all fronts, including boiler, wheelsets, tender frames, heavy motion, pipework and electricals. Design work for the extensively modified and improved cylinder block is complete, with the focus now turned to adaptation of the Lentz rotary cam poppet valve gear to overcome deficiencies in the original design.
Ian Matthews (Fabricator & Fitter) and Ed Laxton (Apprentice Machinist) unwrapping the coupling rods at DLW – A1SLT
Our fundraising is also moving forward well. The monthly ‘P2 for the price of a pint of beer a week’ Covenant scheme has already attracted over 940 Covenantors. Our Dedicated Donation scheme has raised over £400,000; The Boiler Club has already recruited over 200 people of its 300 members target; The Mikado Club and The Cylinder Club are now closed having reached their targets and together raised over £375,00; and The Founders Club had a target of 100 members but thanks to the early enthusiasm of our supporters we recruited over 360 members. The Tender Club already has almost 90 members just 20 months from launch and The Pony (Truck) Club – only launched in mid-April – has already passed its 20 members initial target.
Altogether this means that over £2.5m has been spent and more than £3.0m raised of the required £5m to complete No. 2007 Prince of Wales within the next three years, if Gift Aid is included. However, to succeed we must raise at least £700,000 every year – a figure we are yet to achieve.
The work involved in manufacturing the motion includes:
- Redesign of coupling and connecting rods to use modern material as pre-war nickel chrome steel alloy proved prone to fracture
- Incorporation of late-pattern BR-type continuous white metal lined crank pin bearing bushes
- Use of the late-A1 design of inside connecting rod which overcame the tendency for the original design of inside connecting rods on LNER ‘Pacifics’ to big-end failure
- Open die forging of six coupling rods, two outside connecting rods and the inside connecting rod and strap
- CNC machining of all rods
- Manufacture of oil box lids, coupling rod knuckle pins, nuts & washers and bearing bush keys
- Casting of leaded gunmetal and phosphor bronze castings of crank pin bearing bushes
- Machining and white metalling of bearing bushes
- Fitting oil box tops
- Assembly of bearing bushes to rods
- Polishing rods.
One of the rods being machined at Stephensons – Stephenson (Engineering) Ltd
The same rod viewed from the other end – Stephenson (Engineering) Ltd
The oil box on the end of the rod – Stephenson (Engineering) Ltd
In May 2018 the Trust placed a £181,000 order with Stephenson (Engineering) Ltd of Atherton, Manchester for the heavy motion. The order included the forging, machining and heat treatment of the nine heavy motion rods – intermediate coupling rod LH/RH, trailing coupling rod LH/RH, leading coupling rod LH/RH, outside connecting rod LH/RH and the inside connecting rod assembly (including strap, gluts and strap nuts and washers) – and the combined piston and rod.
Progress to-date on the heavy motion includes:
- Six coupling rods: intermediate coupling rods (between second and third coupled wheelsets) are at DLW and have been fettled and polished to a mirror finish; leading coupling rods (between first and second coupled wheelset) have been machined and have been delivered today to DLW; trailing coupling rods (between third and fourth coupled wheelset) have been forged with machining starting in the New Year and delivery to DLW expected in early February 2021
- Two outside connecting rods: forging has started, to be followed by heat treatment, then machining and delivery expected at the end of April 2021
- Inside connecting rod and strap: inside connecting rod has been forged and the strap is in the process of being forged, to be followed by heat treatment and machining with delivery to DLW expected at the end of March 2021
- Bronze white metal lined rod bushes: taking shape at Locomotive Maintenance Services Ltd, Loughborough, with the first four bushes for the intermediate rods expected to be delivered before Christmas 2020.
In April 2018, we launched a new appeal to raise the funds to manufacture the motion for No. 2007 Prince of Wales. The Motion Club was established with the aim of raising £210,000 from 175 supporters each donating £1,000 (plus Gift Aid) to the project in up to eight payments of £125 by standing order. The appeal started well and in just seven weeks it had already reached over a quarter of its target. Within three months, we had recruited over 140 members, with around £170,000 pledged, including Gift Aid. You can join The Motion Club here.
Mark Allatt, Trustee, The A1 Steam Locomotive Trust, commented, “We are delighted with the support the project to build Britain’s most powerful steam locomotive has received since its launch seven years ago. With over £2.5m spent and more than £3.0m donated to-date of the required £5m, we remain on-track for completion within three years. However, to maintain this progress we need to raise £700,000 per year and we are still seeking to recruit members of The Motion Club in order to complete the funding for the heavy motion as well as additional “P2 for the price of a pint of beer a week” regular donors or covenantors.
“The delivery of the second pair of coupling rods for Prince of Wales is a major step forward for the project, especially given the limitations of working during the COVID-19 pandemic. The machining of each rod by Stephenson (Engineering) takes around 100 hours. The next steps in the manufacture of the heavy motion include: the heat treatment of inside connecting rod and strap; machining of trailing connecting rods; delivery of new bronze rod bushes which will be pressed into intermediate coupling rods; and altering the design of the oil lids, commencing their machining and fitting to oil boxes.”