Arguably the finest miniature live steam
locomotives of Edwardian times were made by James Carson &
Co. of Cricklewood, North London. Here they are at the 1911
Model Engineer Exhibition. We don't know if the gentleman on the
stand is Carson himself, but the large scale 'Great Bear' at the
back of the stand is quite possibly the one made for Sir
Berkeley Sheffield and now preserved by the Scunthorpe
Society of Model Engineers
Today, the best known Carson survivors are the Gauge 1 and Gauge
3 'Experiment' 4-6-0's. Here's a clutch of Carsons with a Jubb
L to R: Gauge 1 'Experiment', Smithies boiler : Gauge 1
'Experiment', Flash Steam : Gauge 2 'Precedent' : Jubb Gauge 2
Gauge 2 Carsons are very rare. One example that does exist is
the Gauge 2 Precursor seen in the above picture (painted green!)
and described in this page from the 1911 Bassett Lowke
catalogue. (Bassett Lowke was always reticent about mentioning
Carson. Maybe the two didn't get on, because it's said that when
Carson went bust in 1913, Bassett Lowke was waiting outside the
building to buy up the assets).
This little engine came to me in a poor state from a trader at
the Warley Model Railway show, where it was held together with
rubber bands! The crank axle was buckled, the boiler covered in
soft solder, much of the tinwork missing and the boiler painted
bright green. However, it did come with a page from Carson's
catalogue of 1911:
The note that the model "is now built with two cylinders" which
seems to date it between 1911 when the catalogue was published
and 1913, when Carson went out of business.
The loco is perhaps unusal amongst Carsons in still having its
original Smithies boiler (described at the time as 'internally
fired'). Our modern fire tube boilers, pioneered in Gauge 1 by
John Van Riemsdijk, were still far, far in the future. This
boiler had been heavily tampered with, having the backhead
fittings held in place by a flood of soft solder. However the
specification (below) says 'Brazed throughout' and that gave us
a chance of restoring it to original condition.
Virtually all surviving Carsons have been re-boilered with
modern boilers, but I wanted to know how well model locomotives
in 1911 actually worked (if at all!).
It's often said that once a boiler has been patched with soft
solder, it cannot be returned to hard solder. I can say that
this is incorrect, because after painstakingly removing every
trace of soft solder by scraping and burnishing with glass fibre
pencils, my Son Paul was able to reflow modern silver solder
around the replica backhead fittings that we had made. Once
repaired the boiler was tested to modern model engineering
standards and easily withstood the 200 psi mentioned in 1911.
The model as acquired. Note the little known LNWR
experimental green livery!
The Carson Precursor boiler as cleaned up. Note the very high
standard of construction, cast bronze backhead and brazed
The Carson backhead as restored, cleaned of soft solder and
regulator bush silver soldered in place.
The burner was a different matter, because there was no existing
design to copy. I settled on a 6 wick layout with 1/4" wick
tubes, all made from thin wall brass tubes. Although Carson said
the model was supplied with tender tanks, none were present and
obviously the tender had been flooded with about a pint of meths
to feed the drip feed burner. The danger of this arrangement can
only be imagined! A modern fuel tank with 'chicken feed'
regulation was made to connect to the burner by flexible pipe.
However, this arrangement far from eliminated the danger of
'flare ups' to which models in this period must have been prone.
Initially the burner was tried with ceramic wicks, which proved
to be too floppy in this large size, aggravating the flaring
problem. Ultimately these were replaced with rolled stainless
mesh, which remains in shape and gives an adequately strong
The crankshaft was straightened, the missing platework replaced
and the chassis run on air. Initially, testing with a very small
amount of meths in a temporary reservoir revealed a very
lacklustre performance. But the model did move under it's own
steam. The first Gauge 2 steam model to do so for a very long
time! Much fettling, including repacking the pistons, which rely
on graphited string, slowly improved matters. It became obvious
that with early models like this, there is no reserve of
performance to make up for shortcomings. Everything has to be
During this time, the lockdown of 2020, an oval of Gauge 2 track
was assembled using vintage Bond's rail very similar in section
to modern code 332. All 2000 sleepers were bandsawed from
hardwood battens and indvidually secured to the track with
stainless crews acting as spikes. The Carson was tested,
fettled, and tested again on this track until it could run a
full lap without stopping. But there was still no sign of the
sparkling performance that Carson allluded to. Slowly things
inproved and with the superstructure added back along with the
restored tender, complete with compartments for meths and water.
The water tank contains a suitably antique hand pump and in a
concession to modern times, an Enots valve.
New baffling was added to the firebox to restrain the flaring
problem and a handheld electric blower with onboard Lipo battery
made for the event that the loco stopped with the blower closed.
(Because of the relatively poor steaming of the Smithies boiler,
the blower consumes more steam than it can produce). Now the
little engine could make several laps of the track and even tow
a tinplate carriage. Then, one day and for no particular reason,
the Carson took off like a scalded cat and ran, with several
carriages for minute after minute without stopping, and at
breakneck speed. That was a real red letter day because at last
the little engine was doing what James Carson had said it would
do, 110 years ago.