Hooves v Wheels
the rise of the motor lorry, the horse remained almost unchallenged where
heavy deliveries within a short radius were required. Brewers, coal merchants,
the railway companies, etc. all relied on the horse. Not until the 1930's
when Karrier and Scammell produced their respective 'mechanical horses'
was the supremacy of the heavy horse threatened.
introduced their Cob 2-ton and Colt 4-ton three-wheeled prime-mover and
trailers in conjunction with the L.M.S. railway powered by a Jowett, 7hp
flat twin engine in 1931, which was upgraded with a larger Coventry Climax
engine in 1933.
introduced their Mechanical Horses of 3-ton and 6-ton capacity in 1933,
using the Scammell engine and Scammell automatic coupling gear which enabled
the speedy changing of trailers. The Scammell M.H. was developed from
the design bought from Napier.
new means of urban deliveries attracted the attention of the trade press
and various comparison tests were published in the early 1930's. One involved a Commercial Motor observer spending a day with the crew
of a Scammell 3-tonner operated by a North London coal merchant, chosen
for their mixed fleet of horse and machine.
The first thing
the observer noted was the lively turn of speed, with 11mph being achieved
when fully laden with 3 tons of coal. The first delivery was to a private
house where thirty sacks of coal were tipped into the coal-hole at the end
of a long sweeping driveway. The Scammell easily manoeuvred to within
4 feet of the hole while the driver remarked that the nearest the horse
could get was the end of the driveway. This saved carrying the sacks seventy
yards with obvious time saving. No mention was made about the saving in
effort by the dray's crew.
A mix of residential
and commercial addresses completed the round and the crew returned empty
to base, achieving speeds up to 14mph. The trailer was quickly changed
for a loaded one and the second round started. The pattern was thus set
for a day's work of four rounds.
At the end of the
day, the Scammell was re-fuelled with 3.5 gallons of ROP spirit and comparisons
made between the work completed by both Scammell and a horse-drawn dray.
It was noted that
the Scammell was able to achieve all the horse was able to and often exceeded
the capability of the horse when room at the customer was tight. Turnaround
times at the end of each round were quicker due to the speed of trailer
change with the automatic coupling for the trailers.
Karrier and Scammell offered kits costing £30.0s.0d to convert horse
drawn drays to use with mechanical horses.
In conclusion it was noted that the mechanical horse would cost £220.0s.0d per annum less to run than the number of horse-drawn drays needed to complete the same amount of work.
Costs per Annum
horses and drays @ daily hire charge of £2 15s 0d.
Difference = £222 1s 0d
The Scammell and Karrier proved to better the horse and Scammell went on to better Karrier, and later Jensen, continuing the concept through the 1950's with the Scarab and into the 1960's with the Townsman when front brake legislation ended the days of the 3-wheeled tractor unit.
from my original article in Vintage Roadscene, Vol 8, 30 (March-May 1992)