John Hobbs discovered more about the Fowler steam ploughing engines that were converted to internal combustion machines by McLaren – in the company of Henry Roskilly, the son of the joint patent holder.
The Patent Application No 15607/35, dated 23 May 1935 and headed ‘Method of Converting Steam Driven Cable Ploughing Engines or Tractors to Internal Combustion Engine Drive’, was submitted by J&H McLaren Ltd of Midland Engine Works, Leeds and one William Wilcock Roskilly from his private address in the same city.
The opening statement of the submission to the Patent Office read: “Steam tractors of this type are now being rapidly superseded by petrol or heavy oil engine tractors, and this invention has for its object to provide a method of converting the former, thereby materially reducing the heavy expenses which would otherwise be incurred in replacing obsolete machines by entirely new ones.
A works photograph of what is almost certain to be Fowler No 14379 Salty with its McLaren addition. HENRY ROSKILLY COLLECTION
“According to this invention the conversion is effected by removing the steam engine from the top of the boiler and replacing it by an internal combustion engine mounted on a suitable frame secured to the existing boiler barrel or the said barrel and smokebox… The existing steam engine including cylinders, connecting rods, link motion work, crankshaft and the smokebox chimney with its base are removed leaving the boiler barrel ansmokebox bare. A substantially rectangular frame is secured to the boiler barrel and smokebox and constitutes a bed on which the diesel engine is mounted. This frame comprises two longitudinal angle irons riveted to the two vertical horn plates, the latter being riveted to the boiler barrel and smokebox. The hornplates are tied together at the front to the front of the smokebox by a cross plate and cross angle irons and at the back to the top of the boiler barrel by a cross plate and cross angle irons.” There follows a very detailed description of the method by which the engine transmits power to the road wheels and to the ploughing drum – precision engineering at its finest.
Now there will be few, if any, who have not heard of the first-named patent applicant, but what do we know about William Willcock Roskilly? That was exactly what I wanted to discover when I recently met his son Henry. I’ve known Henry, named after Henry McLaren he told me, for a number of years now and knew that he has a passionate interest in the Leeds company, but it was only when I began to dip into John Pease’s book, The History of J&H McLaren of Leeds, that I began to realise the significant part that Henry’s father, yes the said William, had played in the days before and during the development and application of the internal combustion engine within the output of what was then a very significant business.
William Roskilly, born in Tavistock, Devon and educated at the local grammar school and then at Leeds University, joined McLarens in 1910, serving regular pupilage until 1913. He was then engaged in the design and construction of steam ploughing engines, traction engines and large electricity generating engines for the ensuing two years, after which he was appointed assistant to the general manager and continued to work for the business until his death in 1949, by when he had been appointed to the post of chief draughtsman – a very worrying eye condition having stopped him from joining the services.
In his earlier years with McLarens, he was very much responsible for the design of agricultural implements and in particular for the very impressive trenching plough. Indeed John Pease considers William Roskilly to be ‘one of the unsung heroes of the company’. But it was the conversion of the ploughing engines from steam to internal combustion power in which I was particularly interested, and in which William had enjoyed such a significant role.
No 14379 Salty in its current state.
Quick reference to the Traction Engine Register shows that three pairs of Fowler ploughing engines were converted to receive McLaren-Ricardo diesel engines: they were Nos 14379/80, 15133/4 and 15348/9 and happily all six are preserved. The first pair were Class BB engines and each received a six-cylinder diesel engine, the second pair were Class K7, and, being shorter than the others, they were each given a four-cylinder McLaren-Ricardo engine, while the final-mentioned pair – Class BB1 – were sufficiently large for each to receive the six-cylinder engine.
The first pair to be converted was Nos 14379/80 and in 1935 they were driven in steam to the McLaren Works in Leeds for the work to be undertaken and afterwards they returned under their own (diesel) power to their owner’s yard near Biggleswade, Bedfordshire. A significant secondary feature of the conversion was the installation on each of a 5hp ‘V’ JAP petrol donkey engine, to be replaced later by one of 8hp since it was considered that the original ones were underpowered, especially in cold weather. The pair of 16hp Class BB engines was new to C Cordon Cooper of Caldecote, Bedfordshire just before Christmas 1917 and they remained in his ownership until September 1934 when they were sold at auction to G Taylor of Redbourn, Hertfordshire. He sold the engines to Mr RG Kendall in 1935, and it was the latter who decided that they should be returned to McLarens to be substantially reconstructed.
