Kerr Stuart 4415

From Festipedia, hosted by the FR Heritage Group
Kerr Stuart 4415
The part restored Kerr Stuart 4415 on display at Harbour Station during the Welsh Highland 100 gala on 24 June 2023
Home Railway F&WHR
Status Undergoing restoration
Built by Kerr Stuart
Built 1928
1928-29 Trials on F&WHR
1934 Sold to Mauritius
1997 Returned to UK
Wheel Arrangement 6wDM
Fuel Diesel

Kerr Stuart 4415 is an early diesel locomotive that was originally tested on the Festiniog and Welsh Highland Railways. After being used on a number of other railways around the world, it has now returned to the F&WHR for restoration.



This 6wDM locomotive is a pioneer of British internal combustion locomotive history. One of the very first British diesel locomotives, it was built by Kerr Stuart in Stoke-on-Trent in 1928 (builder's number 4415). Sister locomotives Nos. 4418/28 and 4432-4 were sent via Robert Hudson to the Sudan Gezira Board during 1929 for use on extensive cotton plantation 60 cm-gauge railways. 4419 in 1928 of 3 ft 6 in gauge went to Roan Antelope Copper Mine in Zambia. Nos. 4430/1 were sold to the 75 cm-gauge Central Railway in Ecuador.[1]

Webb gives the following background to the development of these locomotives[1]:

"The return of Kerr Stuart to the diesel locomotive market occurred in 1928, when a new highly standardised locomotive range was introduced. The range was produced and marketed with success under the direction of W.K. Willans, who had previously been with the Sentinel Wagon Works Ltd. at Shrewsbury, and largely responsible for the successful Sentinel geared high-pressure steam engines used in locomotives, railcars and road vehicles. With so much experience, Willans produced at Stoke-on-Trent a basic narrow gauge range of locomotives, powered by either diesel or high-pressure steam engines and using a common underframe, running gear and final drive unit. Two and three axle variteties were built and it was a simple matter to accommodate a number of rail gauges simply by changing wheel-axle sets.

Although mainly diesel-powered locomotives were built, a few steam examples were supplied and worked successfully. The locomotives were built on a stock basis so that orders could be quickly met. In all cases the McLaren engine was used and 30, 60 and 90hp locomotives were built. The gearbox and final drive units built by Kerr Stuart, using David Brown bevel wheels and spur gears, were located at the front of the locomotive, driving to the axles by roller chains. The 60 and 90hp models had JAP petrol starting engines fitted"

4415 at Dinas in 1928

No 4415, the first example of the range, was used as a demonstration locomotive by its maker. It came to the Welsh Highland Railway for trials in the summer of 1928. It proved very capable for work on the Bryngwyn branch and some media coverage resulted.[2] It was then fitted with a vacuum brake by its makers and used on the WHR winter passenger service. Its successful use in this duty led to inspection by an LNER representative.

The Colonel Stephens Railway Museum web site shows it as it ran on the WHR.

In March 1929, Colonel Stephens had the locomotive transferred to the more profitable work of moving slates at the bottom end of the FR. For this purpose the cab was cut down so it would pass under Rhiw Plas Bridge.[3] He could not afford to purchase it even though clearly impressed by its performance, and inevitably it returned to Stoke in August 1929.

Use around the world[edit]

After leaving Wales, the loco was lent to Sir Lindsay Parkinson & Sons who were constructing the East Lancs Road between Liverpool and Manchester.[4] It then had a spell in Ireland on the Castledearg and Victoria Bridge Tramway, after being converted to 3 ft gauge. The locomotive was bought by the Hunslet Engine Company as it was still at Kerr's Stoke on Trent factory when it closed down in 1930. After being taken to the Hunslet works, it was overhauled and later sold for service overseas, via Robert Hudson Ltd., to Union Vale Sugar Estate, Mauritius. Hunslet supplied a new McLaren engine in 1945.[1] It hauled sugar cane at the Union Vale Sugar Factory until 1971, being plinthed subsequently.

On 10 October 1997, the locomotive returned to the Ffestiniog Railway, through the initiative of the Greenwich and District Narrow Gauge Society, having been generously donated by its former owners in Mauritius; Olivier Jaubert handled the negotiations. The FR Trust met the costs of repatriation. It was in store at Minffordd for a number of years. The diesel engine (not the original) required replacement, and a seemingly suitable unit was acquired. The bodywork required renewal and parts of the chassis also required work, the major items being new drive sprockets and roller chains.


An appeal for its restoration was re-launched in 2005, in the hope of having it in at least presentable static condition for the 80th anniversary of its first spell on the WHR and FR in 2008-9. However, the appeal was ultimately denied.

Since April 2008, KS4415 has been jointly owned by the Greenwich & District Narrow Gauge Railway Society and FR Heritage, the move from FR Co. to FR Heritage was made to help facilitate in obtaining funds from sources such as PRISM and the National Lottery Fund once sufficient funds have been raised from donations first.

Starting in September 2014, the locomotive is being restored to operation by a dedicated volunteer team at Boston Lodge. As of September 2017, the rolling chassis had been completed, and attention was turned to the engine and gear box. The replacement engine previously acquired was found not to be suitable, however another engine - of the same type as the original of 1928 - was found at Armley Mills Museum in Leeds. Following negotiations it was agreed that the museum would loan the engine for use in KS4415 and it is now undergoing restoration.[5] By late 2021 the new crank shaft had been received from the manufacturer and work was ongoing to build a new diesel pump and injector system. This seems to have been a rapidly developing aspect of these engines and the timeline for various different drawings and samples from other engines is uncertain. The patterns to produce the new castings required are completed. Work has also been done on the donkey engine starting mechanism.[6] By 2023 the bodywork was progressing well and it was erected with temporary bolts used in place of the long term rivets. It appeared at WHR 100 but contained no engine.[7]


See also[edit]


  • Bradley, Vic (1993) [1992]. Industrial Locomotives of North Wales. London: Industrial Railway Society. ISBN 0-9010-9672-5. OCLC 27769657.

  1. ^ a b c Webb, B (1973). The British Internal Combustion Locomotive: 1894 - 1940. Newton Abbot, Devon, UK: David & Charles. pp. 60–61.
  2. ^ J. W. Willans (1964) "Pioneer "Modern Power" on the Festiniog", Ffestiniog Railway Magazine, Issue 26, page(s): 17
  3. ^ "History: At work on the FR". Kerr Stuart 4415 website. Retrieved 11 March 2018.
  4. ^ "History: Early". Kerr Stuart 4415 website. Retrieved 10 March 2018.
  5. ^ Tidy, David. "Engines Update". Kerr Stuart 4415 blog. Retrieved 15 September 2017.
  6. ^ David High "Kerr Stuart 4415", Festiniog Railway Heritage Group Journal, Issue 147, page(s): 7-11
  7. ^ David High "Kerr Stuart 4415", Festiniog Railway Heritage Group Journal, Issue 154, page(s): 16-134

External links[edit]