Thornycroft marine engine - seeking information

A friend of mine is researching a sea-going vessel and wants to find out more about the engine she was fitted with. The main complication is that the vessel has been missing since 1934, and the engine is probably at the Bottom of the Deep Blue Sea.

Surviving records tell us that she was fitted with a 2-cylinder oil engine by Thornycroft, with 2 cylinders of 6" bore and 8" stroke. It was rated at 18 nominal horsepower, and appears to have been fitted in 1927.

The engine seems remarkably small for the size of the vessel. It is notoriously difficult, if not impossible, to work out the actual brake horsepower of an engine from its nominal rating, so I wonder if it is possible to get an answer by approaching it from a different direction. Given the information we have, is it possible to identify a possible or probable engine model? If so, can we find out the BHP rating of that engine? And, better still, are there photographs or catalogue scans we could access?

Over to you, Thornycroft experts... and thanks in advance.

George B.

Not a Thornycroft expert, but I do have a marine engine book dated 1927. It lists a twin cylinder petrol engine which is about half the size of the engine you refer to, but gives the horsepower as 9hp at 1000 rpm driving a 17 inch prop. So the rating for this engine of 18 horsepower doesn't seem unreasonable.

Just a thought, you say the engine was fitted in 1927 so is it possible it was an auxiliary engine fitted to a sailing vessel?

Sound like it could have been a Thornycroft Handybilly engine. There are pictures on the net and there is one in the marine engine section of the Internal Fire museum.

Just a thought - maybe the narrowboat fraternity could offer some advice.

Also http://www.thornycroftparts.co.uk/

philipagri wrote:Sound like it could have been a Thornycroft Handybilly engine. There are pictures on the net and there is one in the marine engine section of the Internal Fire museum.

Handy Billy was petrol, I thought the one the OP referred to was an oil (diesel) engine? I remember their engine factory in Reading where I grew up but didn't take much notice of 'boat engines' back then.

Pete.

Foden wrote:

philipagri wrote:Sound like it could have been a Thornycroft Handybilly engine. There are pictures on the net and there is one in the marine engine section of the Internal Fire museum.

Handy Billy was petrol, I thought the one the OP referred to was an oil (diesel) engine?  I remember their engine factory in Reading where I grew up but didn't take much notice of 'boat engines' back then.

Pete.

My 1932 Petter Stationary and Marine Oil Engine catalogue includes both diesel and petrol/paraffin engines. It clearly shows and describes the Petter M Type for working on paraffin as an Oil Engine.

An engine that starts on petrol and then switches to paraffin is often described in that period as an Oil Engine while Diesel engines of the period are equally often described as Heavy Oil Engines.

The Thornycroft engine could have been of either type.

mattblack wrote:Just a thought, you say the engine was fitted in 1927 so is it possible it was an auxiliary engine fitted to a sailing vessel?

Matt, I've enquired further and discovered that the register entry states "NE27" which has been interpreted by others as New Engine, 1927. It seems possible that it is actually a model number for the motor. Did Thornycrofts make a model NE27 at any time?

Yes indeed, it seems she was a sailing vessel, so it would have been an auxiliary engine. Sorry if I seem a bit vague about some of this, but I'm getting the information at second hand.

Anyway, thanks for the contributions so far - keep 'em coming.

George B.