Six driving wheels for Clan Hengist to be built in a year
ALL six driving wheels for new BR Class 6 Clan Pacific No. 72010 Hengist
are to be built over the next year by William Cook Cast Products, in one of the biggest milestones for the project.
The firm, which was also the principal commercial sponsor for newbuild A1 Peppercorn Pacific No. 60163
Tornado, will make the wheels based on two patterns – one for the centre driving wheel and the other for the leading and trailing wheels.
The patterns will be made using traditional methods, assisted by laser scanning of the wheels on
Hengist’s ‘big sister’ BR Britannia Pacific No. 70013 Oliver Cromwell,
based at the Great Central Railway’s Loughborough depot. The scan will define any missing details for the finished patterns. From these, the wheels will be cast and then proofmachined, ready for finish machining to suit the axles and tyres.
The work will take between six and 12 months and will be worth more than £100,000 to the Standard Steam Locomotive Company Ltd’s project.
The firm’s Sir Andrew Cook CBE said: “Britain is now entering the second and most hazardous stage of the heritage rail movement which began some 60 years ago. Preserved locomotives are requiring hugely expensive repairs, including new boilers, and the generation of men whose knowledge and enthusiasm preserved them in the first place is dwindling as death takes its inevitable toll.
“In this context, new-builds are ever more important if the working steam locomotive is not to become a thing of the past. As both a life-long rail enthusiast and experienced manufacturer of the many kinds of cast parts a steam engine requires, I consider it my duty to our industrial heritage to do what I can to assist.
Last in UK?
“The Clan class was a pretty engine, but no example escaped the scrapman’s torch. Hengist is a state-ofthe art engineering project based in the heart of Sheffield and could even be the last Pacific locomotive built in the UK. Such iconic locomotives are a major part of our history, without which future generations would never experience the sight, sound, and even smell of a working steam locomotive.”
Andy England, managing director of CTL Seal in Sheffield, where Hengist is based, said: “This is a fantastic development for the locomotive; the project is building a real head of steam now. You can really see the engine taking shape.
“It is an exciting challenge as we are recreating the engine using the original 1950s design but employing 21st-century engineering techniques to make it greener, cleaner, and more efficient.”
The first Clan was built in 1952, but due to a steel shortage and the modernisation of the rail network, only 10 of a planned 118 were completed and none survive.
Precision engineering company CTL Seal Butterthwaite Lane, Ecclesfield, was chosen to build the 11th example using a combination of volunteer expert engineers and the firm’s experienced design and manufacturing team – known as the Sheffield Steam Team.
The new engine design can be more easily be adapted to take advantage of alternative manufactured fuels being developed, using biomass as a key component.
To make Hengist greener, two key changes are going to be made. Firstly, boiler pressure is to be increased by 25psi from 225 to 250 to extract more energy from the fuel. Secondly, a 21st-century exhaust system, which improves combustion and reduces back pressure on the cylinders, will be designed. Computer simulations suggest that these two improvements will help Hengist reduce harmful greenhouse gas emissions by up to 10.5%. The higher boiler pressure and the improved exhaust system also means that it will be 22% more powerful and will be able to pull more coaches or run faster uphill, giving greater operational flexibility for running on the main line.
Even more improvements
When new, the original Clans had one of the lowest fuel consumptions of any BR Standard, and Hengist is expected to improve on this.
As well as the improved exhaust system and higher boiler pressure, other improvements are going to be made to the pistons and valves to reduce steam leakage and reduce wear, through improved materials and lubrication.
As a total of 999 BR Standard locomotives were built up to 1960 when production ceased, Hengist will become the 1000th.
➜ The Standard Steam Locomotive Company Ltd, a registered charity, needs to raise a total of £4 million to complete Hengist by the target date of 2029, and donations are invited. To find out more about the project and to make a one-off donation, visit www. gofundme.com/hengist