Trevithick: Surviving Engines
c.1798 Model Steam Carriage
A working model steam carriage is on display at the Science Museum (see photos). Reference to the photograph indicates how the operating cycle is controlled: a quarter-turn four-way cock is alternately turned through 90 degrees to allow admission and exhaust to and from the cylinder. The valve handle is moved by the slotted vertical rod connected to the engine crosshead. Dickenson and Titley dated this to 1798, and stated that its history can be traced back to 1810 when it was at the Soho Foundry in Ancoats, Manchester, of David Whitehead and Co. Their information presumably came from Francis Trevithick's Life of Richard Trevithick[3], which in turn references a 'Letter from Mr. Joseph Radford, in 1850 states that it had been in his family since 1810.' Joseph Radford was probably Joseph Radford, a Manchester ironfounder. The relevant text is: 'A model of Trevithick's, now in the Kensington Museum, spoken of by Mr. Radford as having come from the engine-works of Messrs. Whitehead and Co., Soho Iron Works, Manchester, is probably one of those spoken of by Mrs. Trevithick as having been made prior to 1800. It is a perfect specimen of a high-pressure steam-engine, with cylindrical boiler, adapted to locomotive purposes. It served as a guide to Messrs. Whitehead and Co., who manufactured engines for Trevithick in 1804.' The former Whitehead & Co's Soho Foundry's stock was advertised for sale in 1808, and the foundry itself in 1810.
c.1804 Engine and Boiler by Hazeldine and Co
1884 'TREVITHICK’S ENGINE AT CREWE.
A few weeks ago, when dealing with the visit made to Crewe by the members of the Iron and Steel Institute during the Chester meeting, we mentioned (vide page 310 ante) the old high-pressure engine of Richard Trevithick, which, thanks to Mr. Webb, has been rescued from a scrap heap in South Wales, and re-erected at the Crewe Works. We this week give page 476 engravings of this engine, which have been prepared from photographs kindly furnished to us by Mr. Webb, and which will clearly show its design.
As we mentioned in our former notice the boiler bears a name-plate with the words “ No. 14, Hazeldine and Co., Bridgnorth,” and it is evidently one of the patterns which Trevithick was having made by Hazeldine and Co., about the year 1804. The shell of the boiler is of cast iron, and the cylinder, which is vertical, is cast in one with it, the back end of the boiler and the barrel being in one piece as shown. At the front end the barrel has a flange by means of which it is bolted to the front plate, the plate having attached to it the furnace and return flue, which are of wrought iron. The front plate has also cast on it a manhole mouthpiece to which the manhole cover is bolted. In the case of the engine at Crewe, the chimney, firehole door, and front of flue had to be renewed by Mr. Webb, these parts having been broken up before the engine came into his possession.
The piston rod is attached to a long cast-iron cross head, from which two bent connecting rods extend downwards, the one to a crank, and the other to a crank-pin inserted in the flywheel. The connecting rods now on this engine were supplied by Mr. Webb, the original ones—which they have been made to resemble as closely as possible—having been broken up. In the Crewe engine as it now exists it is not quite clear how the power was taken off from the crankshaft, but from the particulars of similar engines recorded in the “Life of Richard Trevithick,” it appears that a small spur pinion was in some cases fixed on the crankshaft, and in others a spurwheel, with a crankpin inserted in it, took the place of the crank at the end of the shaft opposite to that carrying the flywheel. In the Crewe engine the flywheel, it will be noticed, is provided with a balance-weight.
The admission of the steam to and its release from the cylinder, is effected by a four-way cock provided with a lever, which is actuated by a tappet rod attached to the crosshead, as seen on the back view of the engine. To the crosshead is also coupled a lever having its fulcrum on a bracket attached to the boiler, this lever serving to work the feed pump. Unfortunately the original pump of the Crewe engine was smashed, but Mr. Webb has fitted one up to show the arrangement. A notable feature in the engine is that it is provided with a feed heater through which the water is forced by the pump on its way to the boiler. The heater consists of a cast-iron pipe through which passes the exhaust pipe leading from the cylinder to the chimney, the water circulating through the annular space between the two pipes.
Altogether the Trevithick engine at Crewe is a relic of the very highest interest, and it is most fortunate that it has come into Mr. Webb’s hands and has thus been rescued from destruction. No one, bearing in mind the date at which it was built, can examine this engine without having an increased respect for the talents of Richard Trevithick, a man to whom we owe so much and whose labours have as yet met with such scant recognition.' [4]
c.1812 Threshing Engine from Trewithen
A high-pressure threshing engine and wrought iron boiler, built for Christopher Hawkins at Trewithen in 1811 or 1812, and used until 1879, were presented to the Science Museum. The machine was briefly described and illustrated with a drawing and photograph by Dickinson and Titley in 1934 [5]. It is a single-acting engine, and a very early example of a trunk engine, having the small end of the connecting rod connected directly to the piston by a gudgeon pin. See here for information on the Science Museum website, including a photo of the single-acting piston.[6].
See here for a photograph of the machine, taken when it was on display in the Science Museum next to the Hazeldine engine. Note the cam on the crankshaft which operates the steam valve.[7]
See also Engineering 1879/06/27
Presumed Trevithick Engine from Staffordshire
'The Engineer' in 1912 described and illustrated a Trevithick-type engine which had been presented to the forerunner of the Science Museum by the Earl of Shrewsbury and Talbot. [8]. See photo. It is preserved at the Science Museum (accession No. 1911-80). From the Science Museum website [9]: 'This engine was employed for general purposes at a salt works at Ingestre, near Stafford, for upwards of half a century; it was disused since 1882, when the works were closed down. It is said to have been removed thither from Brereton, near Rugeley, where it had been used in winding from a coal pit. Nothing is known as to the maker of the engine, but it exhibits several features that were peculiar to the designs of Richard Trevithick. ....'. The entry lists 15 parts, including a feed water heater.
The engine differs from the other survivors in that its cylinder was not embedded in the boiler.
See [5] for a photograph of the engine, slightly clearer than the images from The Engineer. It will be seen that the quarter-turn valve for steam admission and exhaust to and from the top and bottom of the cylinder is located in a manifold at the mid-height of the cylinder.
From the 1912 article:-
'Not for a long time has so interesting a relic been added to the unique collection of early steam engines at South Kensington Museum as the one lately presented by the Earl of Shrewsbury and Talbot, K.C.V.O. It has been re-erected in the far left hand corner of the annexe to the central machinery hall, and consists of a single-cylinder return crank engine of the vertical type, which there is every reason to consider it being one of Richard Trevithick’s design. Whilst it bears no maker’s name nor any means of direct identification, it presents so many well-known Trevithick features that it may be pretty certainly set down as a product of the ingenuity of the Father of High-pressure Steam. The engine was employed for over fifty years, down to 1882, at some salt works at Ingestre, Staffordshire, on the Earl’s estate. Prior to that it had been used for the winding at a colliery at Brereton, near Rugeley, and is thought to have been built at Bridgnorth. It is known that Haseldine and Co, of that place, built many engines to Trevithick’s design, under agreement with him. The engine is somewhat later than the other examples of his, close by, and is therefore of peculiar interest in enabling the course of gradual improvement to be easily followed.
Almost everything about the machine is of cast iron, and probably its original boiler was too. This, however, had long disappeared - they generally burst - steam having been supplied at Ingestre by an egg-ended boiler, 8½ ft long by 3 ft in diameter, set with a partial wheel draught and working at 35 lb pressure. The cylinder is 7 inches by 24 inches, quite unlagged in any way now. Its bottom flange is one inch thick, held down by four bolts to a base-plate 7/8 inches thick at the sides, but thickened up immediately under the cylinder. This plate is attached by two bolts on each side to cast iron frames supported on the jaws of Y-shaped castings which support the whole. These frames are 20 inches apart, but should have been another inch or two, as they have had to be chipped on the bottom of the inner sides to permit the long return connecting-rods to clear them. They barely do it now. The connecting-rods are about 6 ft long or a little more, of round section 1¾ inches diameter in the middle, tapering to 1½ inches at the ends. They are worked by a crosshead running in vertical guides bolted to the top of the cylinder. From one side of this guide descends a tappet rod, some 6 ft length and one inch diameter, on which are two adjustable tappets which strike the lever of a four-way cock. The tail of this lever has a leather strap fixed to it to limit its fall below the point when the tappet can again strike it. There is no governor, a stop cock on the steam pipe answering instead. There is a bridle for holding the four-way cock in its place and preventing it from working out. The exhaust steam passes to a feed-water heater, somewhat on the principle described in Trevithick’s patent No 2599 of 1802, which shows that he even then appreciated the value of the latent heat contained in it. The feed heater consists of a cast iron casing surrounding about 4 ft of the feed pipe, which passes through stuffing-boxes at each end. Iron loops prevent the casing from shifting, but owing to exigencies of space the heater is placed about one foot in advance of its proper position.
The driving axle, like everything else almost, is of cast iron. On its left end, as you face the steam port side of the cylinder, is a spur wheel about 14 inches in diameter having twenty-two teeth 4½ inches broad. What this wheel drove is not now clear, but the plunger feed pump, 2⅛ inches diameter by 5½ inch stroke, is worked from a pin driven into the boss of the wheel. On the opposite end of the crank shaft are two wheels, that nearest the engine being a cast iron fly-wheel 8 ft in diameter, of characteristically Trevithick design, with only four spokes. These spokes are slightly tapered - 3 inches thick at mid-length and 2½ inches at the rim. These dimensions include a web cast on the inner side. The rim of the wheel is 2 inches thick and 3½ inches deep, very roughly cast on the outer side. As a counterpoise a casting 3 ft 8 inches long and the same depth as the rim is attached to the latter outside, opposite the crank. Three bolts hold it to the rim, passing through the holes 1½ inches long by 1 inch long. In fact, there are four or five of these holes in the rim between each arm or spoke. Outside the fly-wheel is a spur wheel 3 ft 4 inches in diameter, with six broad spokes cast with an inner web. There are fifty-four teeth 1¼ inches deep, but at a later period an iron band 4 inches wide and welded in two places has been shrunk on over them, evidently for the purpose of driving something by means of a belt. The iron band is ½ inches wider than the wheel, so that the teeth could not catch anything. The crank cheeks and the wheel seats are 4½ inches square, the portion of the axle between the bearings of the two connecting-rods being of the same size. These bearings have a raised circular cheek or web on each side and are 2½ inches apart, leaving room for brasses of about that width. Between the faces of the inner cheeks is 15 inches.
The axle bearings, 4 inches long, are at the bottom of the Y-shaped constructions which support the cross frames carrying the cylinder, these constructions consisting of two pieces each, cast with mortices, which assist the bolts to prevent any side movement. To counteract the vibration and shake, and to keep the whole affair steady, holding-down rods run from the top of the crosshead guides to the wooden beams on which the engine stands. These guy rods are of wrought iron, about 8 ft long and an inch in diameter, of round section. The wooden beams in question have been partly renewed, being much decayed in places. They rest upon dwarf walls of five courses of masonry, and are 9 inches wide by 5 inches thick. The space enclosed is 3 ft 4 inches wide by about 6½ ft in length. An excavation had to be made on each side, one to take the lower part of the fly-wheel, the other the feed pump. A good deal, but not all, of the necessary piping remains joined with flanges having three bolts to each joint. They are thickened up for a couple of inches half way and are rather roughly cast. File marks are still very visible on them, and also on the side of the cylinder. The internal diameter of the pipe connections seems to be 2½ inches, the area of both steam and exhaust ports in the four-way cock is 1.25 square inches.
The engine is, of course, only small, but with the exceptions of the absurd 8 ft fly wheel, pretty compact. It is supposed to have developed 5 horsepower at 45 revolutions per minute and 25 lb. effective pressure. The loss of heat from the cylinder and steam pipe, if they were really unprotected as they now are, must have been considerable, and makes it doubtful whether the two older Trevithick engines close by, both of which have a single cylinder sunk in the boiler, would not be more efficient. As an example of the extent to which cast iron could be used in machinery of this sort it is perhaps unique.'
Remains of a Trevithick-type Steam Engine and Boiler
The Science Museum collection includes a Trevithick type cast iron steam boiler with enclosed engine cylinder, which constituted a stationary or semi-portable engine/boiler unit. Stated to have been built by Oak Farm Ironworks, Dudley, c.1845. However, the design and construction appear more consistent with the first decade of that century. Object number 1881-57, credited to E. B. Marten. See here for brief description and photos. The photos show the return flue as removed from the boiler, and the boiler minus its flue. Protruding from the boiler is the engine cylinder, complete with piston road and crosshead.
The cylinder casting, piston, rod and crosshead are on display at the Museum of Iron, one of the Ironbridge Gorge Museums.
1819 Hydraulically-operated Pumping Engine from Winster
This machine, on display in the Peak District Mining Museum in Matlock Bath, was found in 1976 in an abandoned mine, 360 ft below Winster in Derbyshire. Designed by Richard Trevithick, castings made by the Coalbrookdale Co. The pumping engine was worked hydraulically, using water pressure from a pump on the surface to operate a pump which delivers water to a drainage sough.
See Also
Sources of Information
- ↑ John Farey: A Treatise on the Steam Engine, Vol 2. Unfinished, in course of preparation in 1827
- ↑ 'Richard Trevithick – The Engineer and the Man' by H. W. Dickinson and Arthur Titley. Cambridge, 1934
- ↑ [1] 'Life of Richard Trevithick' by F. Trevithick: Volume 1: Chapter 7
- ↑ Engineering 1884/11/21
- ↑ 'Richard Trevithick – The Engineer and the Man' by H. W. Dickinson and Arthur Titley. Cambridge, 1934
- ↑ [2] Trevithick's patent 1802, high pressure steam engine, constructed 1811 for threshing purposes at Trewithen, in use till 1879
- ↑ [3] Getty Images: Science & Society Picture Library: Trevithicks high pressure steam engine, 18
- ↑ The Engineer 1912/06/21, p.660
- ↑ [4] Science Museum: Early high pressure steam engine and feed water heater of Trevithick type