Evolution of the Steam Locomotive

We have previously, upon more occasions than one, shown the important position occupied in the evolution of the steam locomotive by the engines built or designed by Timothy Hackworth. We now have to give an account of his last locomotive, the “Sanspareil No. 2.”

A comparison of the drawings of this engine (copies of which are in our possession) with Hackworth’s earlier efforts of 20 years before, clearly discloses the remarkable strides made in the improvement of the locomotive during that period, and also most clearly shows that in 1849 Hackworth was still in the very van of locomotive construction, even as he had been in the days of his “Royal George.”

The “Sanspareil No. 2” (Fig. 56) was constructed by Timothy Hackworth at his Soho Engine Works at Shildon. The patent was obtained in the name of his son, the late John Wesley Hackworth. We are indebted to the executor of the will of Timothy Hackworth for many of the following details concerning the engine now under review.

The locomotive was of the six-wheel “single” type, with outside bearings to the L. and T. wheels, and inside bearings of the driving wheels. The cylinders were inside. A cylindrical steam dome was placed on the boiler barrel close to the smoke-box. The fire-box was of the raised pattern, and on it was an encased Salter safety valve. Cylindrical sand-boxes were fixed on the frame-plates in front of the driving wheels. The principal dimensions of the engine were:—Driving wheels, 6ft. 6in. diameter; leading and trailing, 4ft. diameter; cylinders, 15in. diameter, 22in. stroke. Weight in working order:—L., 8 tons 6 cwt.; D., 11 tons 4 cwt.; T., 4 tons 5 cwt. Total, 23 tons 15 cwt.

It would be well if we mentioned the principal novelties in construction—viz.: Welded longitudinal seams in boiler barrel; the boiler was connected to the smoke-box and fire-box by means of welded angle-irons, instead of the usual riveted angle-irons; the lagging of the boiler was also covered with sheet-iron, as is now general, instead of the wood being left to view, as was at that time the usual practice.

A baffle-plate was fitted at the smoke-box end of tubes, as well as at the fire-box end.

The valves were constructed under Hackworth’s patent, and were designed to allow a portion of the steam required to perform the return stroke to be in the cylinder before the forward stroke was completed, and thus to form a steam cushion between the piston and cylinder covers. Such working was said to economise 25 to 30 per cent. of fuel.

The engine conveyed 200 tons 45 miles in 95 minutes, consuming 21 cwt. of coke, and evaporating 1,806 gallons of water. She also drew a train of six carriages over the same distance without a stop, in 63 minutes, with an expenditure of 13 cwt. of coke and 1,155 gallons of water.

Upon the completion of this engine, J. W. Hackworth sent the following challenge to Robert Stephenson:—

“Sir,—It is now about 20 years since the competition for the premium of locomotive superiority was played off at Rainhill, on the Liverpool and Manchester Railway. Your father and mine were the principal competitors. Since that period you have generally been looked to by the public as standing first in the construction of locomotive engines. Understanding that you are now running on the York, Newcastle and Berwick Railway a locomotive engine which is said to be the best production that ever issued from Forth Street Works, I come forward to tell you publicly that I am prepared to contest with you, and prove to whom the superiority in the construction of locomotive engines now belongs.

“At the present crisis, when any reduction in the expense of working the locomotive engine would justly be hailed as a boon to railway companies, this experiment will no doubt be regarded with deep interest as tending to their mutual advantage. I fully believe that the York, Newcastle and Berwick Railway Company will willingly afford every facility towards the carrying out of this experiment.

“Relying upon your honour as a gentleman, I hold this open for a fortnight after the date of publication.

“I am, Sir, yours, etc., John W. Hackworth.”

We do not think Robert Stephenson accepted the challenge; at all events, no records of such a competition have ever been made public, and had it taken place the victor would have doubtless well published the result.

The “Sanspareil” frequently attained a speed of 75 miles an hour on favourable portions of the line. She was sold to the North Eastern Railway by the executors shortly after the death of Timothy Hackworth, something like £3,000 being obtained for the engine, which continued to work upon the North Eastern Railway until recent years, having, of course, been rebuilt during the long time it was in active service.

We have now to describe another specimen of the locomotives constructed by the celebrated firm of Bury, Curtis and Kennedy. This locomotive was one of the last engines built by the firm before its final dissolution. The “Wrekin” was a six-wheel engine with inside bar frames and inside cylinders, and was constructed for the Birmingham and Shrewsbury Railway in 1849.

The special points noticeable in the construction of the engine in question are the width of the framing, which was arranged horizontally instead of vertically, and only two bearings to each axle. The axle-boxes of the leading wheels were bolted to the frames, those of the other wheels being welded to the frames, and the cylinders were also directly affixed to the framing. An advantage claimed by the builders, as resulting from the method of construction employed, was that the weight being placed entirely within the wheels, such weight had a tendency to press down the axle between the bearings, and so counteract the constant tendency arising from the flanges of the wheels, when pressing against the edge of the rails, especially in passing round curves.

The cylinders were 15in. diameter, the stroke being 20in. The driving wheels were 5ft. 7in. diameter, the leading 4ft. 1in. and the trailing 3ft. 7in.

The boiler contained 172 brass tubes, 11ft. 6in. long and 2⅛in. external diameter. The heating surface was: Tubes, 1,059 sq. ft.; fire-box, 80 sq. ft.; total, 1,139 sq. ft. Grate area, 15 sq. ft.

No steam dome was provided, the main steam-pipe being of iron, with a longitudinal opening ³/₁₆th inches wide along the top; this pipe extended to the smoke-box, at which end of it the regulator valve was placed; the actuating-rod passing through the main steam-pipe from end to end. Two encased Salter safety valves were fixed on the fire-box. The wheel base of the “Wrekin” was: leading to driving, 8ft. 1in.; driving to trailing, 6ft. 11in.

In 1849 the Vulcan Foundry Company supplied the Caledonian Railway with an engine known as “No. 15.” In general appearance the locomotive was very similar to Allan’s “Velocipede” engine on the London and North Western Railway.

“No. 15” (Fig. 57) was a six-wheel engine, with inclined outside cylinders, 15in. diameter and 20in. stroke. The driving wheels were 6ft. diameter, leading and trailing wheels 3ft. 6in. diameter. The boiler barrel was 9ft. 9in. long and 3ft. 6¾4in. diameter, containing 158 brass tubes of 1¾in. external diameter. Wheel base, L. to D., 6ft.; D. to T., 6ft. 6½in. The chimney was 6ft. 6in. high; on the centre of the boiler was a man-hole, surmounted by a column safety valve of Salter’s pattern, the blowing-off steam pressure being 90lb. The steam dome was of brass, placed on the raised fire-box, and surmounted with a second Salter’s safety valve. The driving and leading wheels were provided with underhung springs, but the trailing wheels had the springs over the axle-boxes. These latter springs were of elliptic shape, and were provided with a screw device fixed on the foot-plate, by means of which the weight was taken off the trailing wheels and thrown upon the driving wheels.

In addition to the semi-circular brass name-plates (i.e., Caledonian Railway) affixed to the splashers of the driving wheels, brass number-plates of diamond shape (12in. long by 6in. diameter) were fixed on the buffer beams of “No. 15.” The tender was supported on four wheels, 3ft. 6in. diameter, and held 800 gallons of water.

During June, 1849, “No. 15” made a number of trial trips between Glasgow and Carlisle, with seven, eight, and nine coaches of an average weight of five tons each, the weight of the engine and tender being 28 tons. On the trips to Glasgow the Beattock Summit had, of course to be climbed. This consists of 10 miles of stiff gradients, varying between 1 in 75, 80, and 88. The run of 13½ miles from Beattock to Elvanfoot, consisting of the 10 miles just described and of 3½ down at 1 in 100, was negotiated by “No. 15” in 33 minutes, with a train of six coaches; with seven coaches the time was 41 minutes, and with a pilot and eleven coaches, 30 minutes, or at the rate of 27 miles an hour. These were considered exceptionally good specimens of hill-climbing performances 48 years back, but are, of course, entirely out of comparison with modern Caledonian records over the same line with much heavier trains.

McConnell, the locomotive superintendent of Wolverton, turned out several remarkable locomotives for the London and North Western Railway, and No. 227, or, as she was generally called, “Mac’s Mangle,” (Fig. 58), was one of these peculiar specimens of McConnell’s design. The cylinders were of large size, being 18in. diameter, with a 24in. stroke; they were outside, as were also the axle bearings—a very uncommon combination. No. 227 was a six-wheel “single” engine, the driving wheels being 6ft. 6in. diameter, and the leading and trailing wheels 4ft. diameter. The fire-box was of the raised pattern, and a Salter safety valve (encased) was fixed on it. A huge steam dome was provided, located, originally, close to the smoke-box end of the boiler barrel, but afterwards (in 1850) placed near the fire-box end, over the driving wheels. The boiler-heating surface of “Mac’s Mangle” was 1,383 sq. ft. No. 227 enjoyed but a short locomotive career, being built in April, 1849, and “scrapped” in May, 1863. It is stated that in consequence of the extreme width of this engine, caused by outside cylinders being employed in conjunction with outside axle-boxes, it became necessary to set back the platforms at some of the stations, so that the engine could clear these erections without coming to grief.

In 1850 McConnell designed a very powerful class of passenger engines for the L. and N. W. R. These are generally called the “Bloomers.” “President” (Fig. 59) illustrates this favourite class of L. and N. W. R. locomotive, when built. The cylinders were inside, 16in. diameter, with a stroke of 22in. The driving wheels were 7ft. in diameter. The heating surface was 1,152 sq. ft. These engines weighed 28¾ tons. (Fig. 60) is from a photo of a “Bloomer” as rebuilt by Ramsbottom.