The first Railmotor -- B&ER No. 29 "Fair Field" was built by William Bridges Adams in 1848 to run on the broad gauge Tiverton Branch. The engine part was later separated and used as a contractor's engine to construct the Yeovil Branch.
Here is Mr. Adams's own account in Road Progress (1850), p. 16:
The earliest practical recogniser of the advantages offered by the light-system was Mr. Charles Hutton Gregory, who advised the Directors of the Bristol and Exeter broad-gauge line to order, for some of their branch traffic, a steam carriage for first-class and second-class passengers. This was built at Fair Field Works, and called the "Fair Field." The vertical boiler of the "Fair Field" was found to involve certain practical difficulties, though an exceedingly rapid and powerful steam generator, and was therefore replaced by a horizontal boiler.
The following are the particulars of the construction and the performance:
The 'Fair Field' steam-carriage was constructed for the purpose of working the Tiverton branch of the Bristol and Exeter Railway, broad gauge. It is an engine and carriage on one frame, the extreme length being 40 feet, hung on six wheels, the two front ones being drivers, 4 feet 6 inches diameter; the middle and trailing wheels are 3 feet 6 inches diameter. Extreme centres of wheels, 28 feet. It is propelled by 2 cylinders, 8 inches diameter and 12 inches stroke, acting on an independent cranked shaft, communicating by side rods to the driving wheels. The boiler was originally cylindrical, placed vertically, and was 6 feet in height by 3 feet diameter. The fire-box was 2 feet 6 inches diameter, with 150 tubes, If inch diameter, with a heating fire-box surface of 20.6 feet, and 216 feet in the tubes. The tank is in front of the boiler, and will hold 240 gallons; it has since been fitted with a horizontal boiler, with a barrel 7 feet 7 inches long, by 2 feet 6 inches diameter. The fire-box is 2 feet 6 inches by 2 feet 3 inches, and 4 feet in height; with 115 tubes, 8 feet long and l5/8 inch diameter. The heating surface in the fire-box is 37 feet, and 325 feet in the tubes.
The body was divided into three compartments, one first class and two second class. Passengers, total number 58.
Performance. The Tiverton branch is five miles in length, and has a rising gradient of 1 in 86.
The maximum load taken up this gradient was, exclusive of the carriage, 31 tons 13 cwt. 2 qrs. 16 lbs. in 11 minutes, being at the rate of over 27 miles per hour. Eighteen trips were run, being a distance of 90 miles, during a space of 9¼ hours, the running time being about 3¾ hours, and the standing time 5½. The consumption of coke per mile 14.8 lbs. Subsequently it was reduced to 13 lbs., and the engine now works with 8.7lbs.
The load consisted of two loaded wagons, each on four wheels of 4 feet diameter. The engine and carriages on 6 wheels, the whole train being on 14 wheels, while the engine and tender alone of the Great Western engines occupy 14 wheels without any carriages.
The 'Fair Field,' ran a trip from Exeter to Bristol, 76 miles — with an extra load of 10 tons behind her, equivalent to 140 passengers total — in 3 hours 37 minutes; 58 being consumed in twelve stoppages, leaving the remaining time 2 hours 39 minutes, being a fraction under 28 miles per hour. The maximum speed attained in this trip was 47 miles per hour.
The maximum speed ultimately attained was 52 miles per hour.
Since writing the above, by the kindness of Mr. Rea, the Locomotive Superintendent of the Bristol and Exeter Railway, who has paid great attention, to this question of railway economy, with a view to determine the saving to the Company by proportioning the power to the work done, the writer is enabled to furnish the following statement of results in every day work on the Clevedon branch of the above railway, on two following days.
FAIR FIELD" STEAM CARRIAGE, CLEVEDON BRANCH,
March 26th, 1850:
TRIPS FROM YATTON TO CLEVEDON.
Average Speed, Miles per Hour.
1. Yatton to Clevedon 24.7
2. Ditto, 1 carriage truck 25.0
3. Ditto, 1 wagon, 23.6
4. Yatton to Clevedon, 26.4
5. Ditto, 23.7
6. Ditto, 1 truck, 24.4
7. Yatton to Clevedon, 22.9
8. Ditto, 24.7
Total consumption of water running 16 trips, or 64 miles = 397½
gallons. Total consumption of coke running 64 miles, including the time
standing in steam — namely, 14½ hours = 5 cwt. Consumption of coke per mile (560 lbs. by 64) = 8.7 lbs. Actual evaporation of water, in lbs., to 1 lb. of coke (397½ x 10 =
3975 by 64) = 7.0 lbs. of water to 1 lb. of coke.
(Signed) MINARD C. REA.
April 1st, 1850.
Bearing in mind that this carriage has accommodation inside for 58 passengers, and that being within nine inches of the rails, it would be very practicable to carry an equal number on the roof without disturbing the centre of gravity, it yet becomes obvious that a very small traffic can be made to pay. But beyond this, thirty to forty tons gross load could, if required, be taken as a train, on the level, at 20 to 25 miles per hour, with small increase in the consumption of coke.
It appears, also, by Mr. Rea's statement, that the steam carriage was far from economically employed; for although she took occasional jobs of hauling wagons and trucks, she was in steam daily fourteen and a half hours; and working only two hours and a half over 64 miles, at rather more than 24 miles per hour. If she had done a full day's work, the cost would of course have been reduced.
Nor is the expense calculated on a niggardly scale. Full wages, for driver, stoker, and cleaner, such as will induce them to use their engine well, and keep a permanent place, are allowed by Mr. Rea — which is true economy.
It appears, therefore, that exclusive of "maintenance of way," which under such light weights would be practically nil — and repairs of the machine — upwards of 100 passengers can be carried over 64 miles for 18s. 3½d.
And repairs on these light machines must be much less than those of the heavy engines, for their wearing surfaces are all proportionately larger, and the weight in motion is less.
Railway Companies cannot too highly appreciate the services of their engineers, who look into the future; and the writer gladly expresses the obligation he and his helpers have been under to Mr. Gregory and Mr. Rea, for their manly aid in enabling the thought of the brain to grow up into the work of the hand. Heart, Brain, and Hand are the Trinity of Progress.