1802 Trevithick Steam Carriage
This amazing machine was built using the original drawing's.
Built by Tom Brogden
Trevithick London Coach Engine 1802
This picture shows the 'Patent specification drawing'.
This information was presented by Mrs Goodrich around 1803.
This is a sketch of the engine and boiler of the steam road coach made by Richard Trevithick in 1802
and tried in the streets of London. The sketch was made by Simon Goodrich, probably in April 1803,
from information given to him by Trevithick.
Although it is known that this coach was actually made and run, few particulars of it are available.
Tervithick himself, in a letter dated 2nd May, 1803, stated that its engine had a cylinder 5.5in. diam.
by 30 in. stroke, and that it made 50 strokes per min. with a steam pressure of 30 lb. per sq. in.
Goodrich's memorandum gives the additional information that the complete engine and boiler weighed
6 cwt., and that the whole was contained in a cylindrical boiler 30 in. diam. and 33 in. long.
In the sketch the boiler shell is placed horizontally and appears to be made of wrought iron about
0.25 in. thick, with flat ends flanged round outside the shell. The furnace tube is 21 in. diam.,
runs the whole length of the shell, and has a flat end with a small water space behind it. The
Grate occupies the whole length of the tube, inclining slightly downward towards the back, and has
an area of 4 sq, ft.
Near the rear end of the furnace two oval tubes, measuring about 7 in. by 5 in.
branch out and return, one on each side, passing through the front plate and being connected by a
breeches tube with the chimney, which is about 6 in. diam., and terminates about 2 ft. above the
boiler. The heating surface is about 21 sq. ft., exclusive of the part below the grate.
The cylinder lies horizontally within and close to the top of the boiler, and the projecting end,
which carries the steam cocks, rests on the coach axle. The four-way distibuting cock is together
with the exhaust pipe leading into the chimney. The coach wheel, 8 ft. diam., is indicated.
From the same drawing's the plan view.
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Drawing of Trevithick Engine and Boiler.
Typical Horse Drawn Carriage of the time.
By William Felton.
London Steam Carriage seen here on the street's of Cardiff.
RICHARD TREVITHICK'S LONDON STEAM CARRIAGE 1803
Technical Data . . . . . . . . . . TSC10
Engine . . . . High pressure, simple expansion steam engine with feed water pump, heater
and steam blast. cylindrical boiler mounted overhanging rear axle, made from 6.5 mm thick wrought iron.
single cylinder, double acting, mounted horizontally, inside the boiler, made from cast iron.
spring operated 4 way valve for steam engine runs in one direction only, (backwards in the patent drawing)
Working pressure . . . . . 2 bar
Cylinder bore . . . . . . . . . 140 mm.
Sroke . . . . . . . . . . . . . . . 762 mm.
Capacity . . . . . . . . . . . . . 11.7 litres x 2
Power . . . . . . . . . . . . . . . 3 HP . . (2 kW) at 50 r.p.m.
Fuel . . . . . . . . . . . . . . . . . Coal
Steering . . . . . . . . . . . . . . Tiller direct to single front wheel.
Transmission . . . . . . . . . Separate gear drive to each rear wheel,
. . . . . . . . . . . . . . . . . . . . . Driver can select drive to either or both wheels
Brake . . . . . . . . . . . . . . . Driver operated lever applying a block to rim of flywheel.
Speed . . . . . . . . . . . . . . 13 km/h.
Range . . . . . . . . . . . . . . about 15 km with 180 ltr water tank.
Dimensions . . . . . . . . . . length 4905 mm
Width . . . . . . . . . . . . . . . 2184 mm
Height . . . . . . . . . . . . . . . 3454 mm
Driving wheel diameter . 2438 mm
Weight, empty . . . . . . . . . 1.9 tonnes
Chassis . . . . . . . . . . . . . . Wrought iron and wood sandwich.
Body . . . . . . . . . . . . . . . . To carry up to 8 people
Cost in 1803 . . . . . . . . . For building the coach less the engine £207 for shipping the engine from Falmouth
to London £20 14s 11d cost of engine not known.
London Steam Carriage on show at Quorn.
London Steam Carriage out on the street's.
London Steam Carriage seen here at Goodwood.
The Birth of the Car
During the late 18th century several engineers considered constructing mechanically propelled carriages
which avoided the need for horses. Horses required a lot of arable land which could be better used to
feed Britain’s rapidly increasing population. James Watt, the leading manufacturer of industrial steam
engines, even went so far as to take out a patent on a carriage propelled by a steam engine but he did
not pursue the idea, realising that the condensing engines of the time were too heavy for the power they
produced to be of practical use in a carriage.
Watt’s rival, the mining engineer Richard Trevithick, was promoting the use of the new “high pressure” steam
engines which some, including Watt, considered to be dangerous. Trevithick had developed these to a stage
where they were much lighter and more efficient than Watt’s engines.
When Watt’s patent ran out Trevithick built a prototype road locomotive at Camborne in his native Cornwall
and in 1801 he ran this several hundred yards up a hill with several people hanging on it and whilst they
were in a pub celebrating the event it set fire to the shed it was in and was destroyed.
Undaunted, the following year Trevithick took out a patent for a practical passenger-carrying steam road
carriage. The patent also described other uses for his new high pressure engines.
The steam carriage was assembled at Felton’s carriage works in Leather Lane, Holborn, London, many of the
engine components having been brought from Cornwall where they were made. The engine may have been tested
in another machine called the Tuckingmill locomotive which was reported to have been stuck on the road
between Camborne and Redruth “because its wheels could not get sufficient grip of the road” and for which
there are no drawings available.
On completion, in July of 1803 the London Steam Carriage was driven about 10 miles through the streets of
London to Paddington and back through Islington with 7 or 8 guest passengers, the streets having been closed
to other vehicles. This was the first trip of a self-powered passenger carrying vehicle in the world. (A
Frenchman, Cugnot had built tractors for towing Napolean’s guns, about 30 years earlier, but these were slow
moving and were not primarily intended to carry passengers). During a trip on a subsequent evening, Trevithick
and his colleague crashed the carriage into some house railings. As a result of the damage done in this or
another accident and also because of lack of sales the vehicle was scrapped and the engine sent to work
in a mill making hoops for beer barrels.
Unfortunately the project was not a commercial success. The steam carriage, besides being expensive to
construct, required two men and a bag of coal to do what a horse drawn vehicle could do with one man and
a bag of hay. Trevithick then built the world’s first railway locomotive. None of his inventions produced
wealth for him and, after a period in South America building pumps to drain silver mines and a life full of
innovation, he eventually died in poverty.
The 8 feet wheels where intended to smooth the rough road surfaces of the time and so avoid the fire being
shaken out and the forked piston rod reduced the distance between the single cylinder and the crankshaft and
was considered a particular novelty. A spring operated valve gear was used to minimise the weight of the
flywheel needed, unlike Trevithick’s industrial engines which required heavy flywheels.
Not all of the details of the machine are known but the patent drawings have survived as have drawings and
some further information made by a naval engineer sent to examine it. (Unfortunately the navy could not use
the engine because of a prohibition on fires in naval dockyards). Further information was recorded later
from eye witness accounts. Although there is no specific drawing of the carriage body, its builder, Felton
published detailed drawings of his horse drawn carriages just before building the carriage for this
machine. These carriages tended to be very similar, to a standardised design which fits the frame shown
in the patent drawings. The replica carriage was constructed to this design but modified to have the door
at the front and the seats sideways because there is insufficient room for doors at the side. This
modification allows more people to ride in it as reported at the time.
The boiler design has had to be modified slightly to meet modern safety standards, but the principal
dimensions and features have been retained but a spring safety valve and a sight glass have been added. It
says a lot for Trevithick’s skill that the new boiler is probably about 100 kg heavier than the original
for the same performance.
A more effective brake has been added also, to augment the simple block rubbing on the flywheel. There
is no drawing for the water tank although the machine clearly had one. Next door to Felton’s works was
a brewery, hence the use of a beer barrel on the replica.
There are two features of the patent drawing which may have been incorporated by Trevithick to put off
unlicensed copiers. If the engine is assembled as in the drawing it would only run backwards. We have
added two extra wheels in the valve indexing mechanism to correct the direction of the engine. It is not
clear what Trevithick intended. Also, the water pump is shown being driven by the valve spring, an
arrangement which would almost certainly have caused the engine to run unevenly if at all. We have
connected the water pump to the crosshead as in most of his industrial engines.
The replica is intended to reproduce the machine with its original performance or at least to be the
first production machine to Trevithick’s drawings.
Click here for another amazing Trevithick machine.
Click here for Hancock's Enterprise Steam Carriage.