The Great Western Society decided to create a 4700 class locomotive and give it the number 4709. Whilst this is a new build project it is being undertaken using a mixture of new parts and others recycled from former Barry scrapyard locomotives. The main donor locomotives are members of the Barry Ten (the ten locomotives that were not originally rescued from Barry scrapyard and instead have hung around for years without any real prospect of restoration)-
|5101 class 2-6-2T 4115 – six of the eight driving wheels and the frame extension.|
|2800 class 2-8-0 2861 – the cylinder blocks.|
|5205 class 2-8-0T 5227 – the axle boxes, horns, fourth axle (axle only) and other various components.|
The main thing that cannot be obtained from the Barry carcasses is the not inconsiderable matter of a boiler.
The plates for the new frames were cut and machined in 2012 at Llangollen and some time later the cylinder blocks were fitted.
During the 2016 further work was completed at the works of the Llangollen Railway on the extension frame. The buffer beam assembly was completed as was the refurbishment of the pony truck pivot (been subject to some machining).
Following this the extension frames were then offered up to the main frames, fitted and bolted up. This effectively gives the locomotive the identity of 4709.
The opportunity was taken to lift the cylinder block and place it on the extension frames. There are eleven bolts on each side to secure the cylinder block to the extension frames and initial indications were that the alignment is a close match which is a testament to Swindon precision engineering when one considers that a cylinder block from a 28XX 2-8-0 will align accurately to an extension frame from a 41XX 2-6-2T.
Initial examination of the cylinder block suggests that it was a quite new casting as there are no liners fitted and there appears to be minimal wear. Before bolting the block to the frames it is intended to carry out a hydraulic test on the cylinder block.
The next job tackled was the completion of the driving wheel set.
Early in 2017 plans were considered to reorganise the project as there were concerns that it was taking too long to complete the locomotive. The plan is that 4709 will be running on the main line by 2023.
By April 2018 the wheelset for the locomotive had had their tyres profiled at the South Devon Railway Engineering and the wheelset moved to Tyseley where the Crankpin collars and lead balance weights are being fitted. The axlebox horn guides had been fitted to the frames at Llangollen.
The final task before the wheeling of the locomotive is undertaken is the restoration of the driving axleboxes from 5227.
In November 2018 the project was anticipated to have progressed to a point where the rolling chassis would be completed following wheeling it in the first half of 2019.
At this stage achieving the target completion of the locomotive in 2022 looks to be optimistic. The forecast is based on having the bottom end and motion complete in 2020 and the boiler and fittings the following year.
The main issue facing the project at the end of 2018 is whether to fit a Standard No 1 boiler from 2861 or build a new no 7 boiler from scratch. Whilst 4700 did carry a No 1 boiler for the first two years of its life the No 7 boiler was designed specifically for the 4700 class. The use of the boiler from 2861 would certainly be cheaper as a boiler built to the No7 specification would probably cost between £500,000 and £600,000.
During 2019 the decision was taken to make a new No 7 boiler as it was considered that the risk and cost would be lower than using the boiler from 2861. It was noted that the skills and craftsmanship of boilersmith engineers had increased in recent years and they have access to modern equipment which makes the production of pressings more affordable. The aim is to build the new boiler in Britain.
The major problem facing the project is the need for funds as in 2017 the income was less than £70,000 whereas about £200,000 is needed each year if the target date for completion is to be achieved.
Whilst the Great Western Society took the decision in 2019 that its locomotives would no longer run on the main line it is intended that 4709 will be built to main line standards and may run on on the national network.
|4709 under construction in Llangollen works-2016|