Power sources at Nutclough Mill
Nutclough Mill 1887 Hebden Bridge Local History Society
Nutclough Mill power sources
The power required to drive the cotton working machinery at Nutclough Mill steadily increased over the years, culminating in the installation of a highly efficient superheated tandem compound steam engine in 1916.
It is convenient to divide the development of the power supply into three time periods in spite of the inevitable overlap which must occur because of the time taken to change from one system to another.
The following is based on the report of the naming of the engine “Unity” in the Hebden Bridge Times and Gazette April 21 1916. The quality of the report shows that the anonymous reporter had a clear understanding of the subject matter. He must have obtained his information directly from the engineering department because of the degree of detail provided, and its accuracy in engineering terms.
Power Sources up to 1873
From the time of its construction (circa 1797) Nutclough Mill was powered by one or more water wheels fed with water from two reservoirs situated in a tributary of Hebden Water above the mill. At some stage a beam engine was added either to supplement the water power or to replace it.
The date of this installation is unknown but it was still in existence when the HBFS purchased the mill in 1873, the purchase including the water rights and an 18 ft boiler. The type of boiler is not known but it was likely to have been a Textile Industry standard Lancashire twin flue type, 18 ft long and about 4 ft 6 in shell diameter which would have been adequate to supply steam to a single cylinder slow running beam engine.
Power sources 1873 to 1916
When the HBFS took over the mill in 1873 it is clear that they realised that even though the original boiler was adequate in size it was in need of replacement because of its age and condition. Their first move was to replace it with much larger Lancashire boiler.
This was followed in 1884 by replacement of the beam engine with a Pickles horizontal engine. Although no details of the new engine are known, it was probably a single cylinder engine operating at 70 psig steam pressure, with steam supplied from the 1875/76 boiler.
This engine served the mill until a new weaving shed was built in 1886. It was then realized that it would be insufficiently powerful to drive the additional load imposed on it by the new weaving machinery together with its original load. The engine was therefore replaced with a larger vertical engine installed by Pollitt and Wigzell. This was most likely to have been another single cylinder engine, but of the inverted vertical type driving directly on to the original output shaft. The magnitude of the increase in size of the new engine relative to its predecessor can be gauged from the fact that a second Lancashire boiler, which was similar to the one installed in 1875/76, was installed at the same time. The March 1912 Insurance Valuation of Nutclough Mill specifies both of the Lancashire boilers then in use as being 30 ft long by 7 ft 6in diameter. The same document confirms the existence of an octagonal chimney at that time.
Power sources 1916 onwards
Nutclough Mill engine - named Unity. Installed 1916. Used by kind permission of John Atack
In 1915 the HBFS Insurers indicated that the working pressure of the two boilers which supplied steam to the engine needed to be reduced from 70 psig to 55 or 50 psig because of age of the 1876 boiler. The directors of the HBFS were advised that the reduction of the boiler pressure by this amount would mean that the existing engine would be unable to meet the current need for power in the mill. They therefore had to consider how to provide sufficient power for the mill both for the short term and for the foreseeable future.
The possibility of using additional electric power from the local electricity works whilst continuing to use the existing steam power system at the reduced pressure was considered, but this was rejected because of the probability that boiler pressure would need further reduction in the future and they would then require yet more electricity, assuming that such electrical power was available locally.
They eventually concluded that the best solution was to replace the engine and boilers with a more up to date, more powerful and more efficient steam engine and steam raising system. This was put in hand immediately and a design produced in conjunction with CWS engineering department.
Orders were placed with the manufacturers of the various parts of the design such as engine, boiler, superheater, and economisers, but the construction was delayed by lack of skilled labour owing to military service demands at that time. The resulting steam plant was inaugurated on 15 April 1916 and could be described as an example of the advanced technology of its day. The advances over the previous steam power system can be summarized as:-
- Two cylinder compound engine - much more efficient than a single cylinder since it produces more power with a lower consumption of steam.
- Larger boiler – is more efficient than two small ones since it uses less coal to produce more steam.
- Superheater – uses energy in the exhaust gas to improve the quality of the steam so that the engine uses less per unit of power output.
- Economisers – extracts the last useable energy from the hot exhaust gas (before the gas is passed to the chimney) to heat the feed water before it enters the boiler. This means that the boiler water requires the consumption of a smaller amount of coal to turn it into steam.
- Surface condenser – condenses the steam so that it can be pumped back through the economisers into the boiler in the form of warm water. The cooling water used to condense the steam becomes heated by the energy extracted from the steam, but it does not mix with the steam (as it does in a jet condenser) so that it can be used for processes such as dyeing.
A summary of the specification of the new steam plant is given below. It is of interest to note that this installation appears to have worked until the mill closed, even though thoughts had already turned to the idea of electrification at the time when it was built.
It may be that some small operations such as sewing machines were increasingly electrically powered, and the provision of facilities in 1916 for increasing the amount of electricity generated in the mill were used in the 1930s, but it is unlikely that full scale electrification would have been feasible until the National Grid became operational circa 1950.
There is no doubt that the Nutclough Mill steam plant was one of the most modern and efficient at the time of its installation, and continued to be so for most of its working life.
916 Power system installation summary
- Type: Two cylinder horizontal tandem compound
- Design steam pressure: 160 psig superheated to 500ºF
- Builders :Wood Bros. Sowerby Bridge
- Power output: 450 indicated horsepower
- Speed: 80 revolutions per minute
- Bore diameters (inches): High Pressure 16, Low Pressure 30
- Piston Stroke : 3ft 6in.
- Flywheel : 15ft diameter carrying 14 ropes of1 in. dia
- Gearing: All rope driven, with provision for an extension to the weaving shed.
Lancashire boiler 9ft dia and 30 ft long.
- Builder: Yates and Thom, Blackburn.
- Boiler pressure: 160 psig
- Superheater: By Sugdens, London
- Steam raised to 500ºF. Slab dampers for isolation.
- Economiser: Greens, Wakefield. with 2 groups of 64 tubes
- Provision made for possible future addition of a second boiler.
- Steam range to provide steam for engine. Dyehouse and mill steam supplied through a pressure reducing valve
- Boiler feed: Engine driven ram pump and standby injector
- Surface type
- Electrical system
- New switchboard to control original 30 kW generator (which had been moved to new engine house) with provision for additional 30kW in future.
Hayes G. (1st Edition 1979, 2nd Edition 1983). Stationary steam engines. Shire Album No. 42.
Hills R.L. (2008)DEVELOPMENT OF POWER IN THE TEXTILE INDUSTRY. Landmark Publishing Ltd.
Watkins G. (1999) THE TEXTILE MILL ENGINE. Landmark Publishing Ltd.
Rope drive for Textile Mills
Prior to about 1870 the nearly all mill drives were by gears and line shafting. These were heavy (particularly the vertical shafts to drive the machinery of the upper floors),required a lot of maintenance and were very noisy. In addition if one of the main gear wheels lost a tooth the whole mill would stop until a repair had been made.
In 1863 experiments were made with round leather ropes. These were made from leather in long strips twisted together into a form of rope and driven by a grooved pulley wheel attached to the flywheel. This type of belt was unreliable because it tended to unravel.
Circa 1870 experiments with flat leather belts were made, but these were not widely used. They were superseded by rope drives using manilla hemp in the late 1870s. These in turn were replaced by cotton rope.
It was not easy to convert multi-storey gear-driven mills to rope drive, because of the need to construct a rope race to allow the drive to reach all the lineshafts on every floor. However rope drive became the standard method of power transmission for new mills from about 1890.
Many older mills were converted to rope drive often when the mill was enlarged to enable more output. This usually required a larger engine to provide the additional power required to drive all the mill machinery.
Rope was made in a 'rope walk' - there were several of these in the area, including a lane still called this near Luddenden.
Nutclough mill is an example of this. In 1916 the new engine was installed in a newly constructed engine house, together with a new boiler, to drive the new weaving shed machinery and the pre-existing machinery. A rope drive system was used to replace the old drive system, which appears to have existed since the days when the beam engine was still operating in the 1870s.
It is of interest to note that the new installation had a fly wheel 15ft in diameter with 14 rope grooves to take 1½ inch diameter ropes. Combe had shown that a 1½ inch diameter rope travelling at 4700 ft/min could transmit 40½ horsepower. Since the new engine rotated at 80 rpm each rope would be travelling at 3770 ft/min and could be expected to transmit 32½ hp. With 14 ropes the maximum power transmissible by the ropes would therefore be 455 bhp. This fits closely with the designed engine output of 450 ihp, which implies a power output at the flywheel (i.e. the power input to the ropes) of about 410 bhp.
(Note. This is based on information in Hills and the Hebden Bridge Gazette and Times)
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