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Phase 1 1866 to around 1870
This is how the ironworks were constructed. At first there were three blast furnaces erected around 1865. They are the tapered cylindrical structures in a line. Within twelve months the market slumped and then recovered in 1869, but there was sufficient demand to keep three furnaces in blast. As trade improved a further three blast furnaces were built to total six by 1873. They were numbered 1 to 6 (left to right). They were built to a contemporary, but 60 year old design by J B Neilson of Glasgow.
From left to right can be seen:
220 ft high Chimney,
Boiler house containing boilers built by Sharp Stewart of Manchester, designed to use blast furnace gas.
Blowing engine house containing two steam driven beam engines. More details here
The six blast furnaces (one is partially obscured and one is totally obscured). The continuous gantry that links the top of every furnace is where the bridge stocker (1) and his gang would manually charge the furnaces with iron ore, coke, and limestone.
The two round topped, brick and iron structures dominating the skyline, contained the lifts.
This is looking roughly North West with Warton Crag on the horizon. The entire arrangement is consistent with a great many other ironworks of the period, not just in Britain. The furnaces are described as open topped but that is slightly misleading. The charge was enclosed within the furnace. A bell arrangement (effectively a giant valve) was opened to accept fresh raw materials.
Furnace 6 in the distance is the only one with a tunnel head that visibly extends above the charging gantry. It is difficult to see if the others are missing or just obscured by pollution.
There is a large diameter pipe running down to ground level to the right of each furnace stack called a downcomer. Gas, collected from the furnace was cleaned and then burned in the hot blast stoves to heat the incoming cold air, and used in the boiler house to raise steam.
There is a line of small wagons at ground level up in front of the blast furnace bunkers, standing on the exchange siding alongside the Down (Northbound) main line. The stone built bunker walls with their distinctive shape are clearly visible and on top is a solitary coke wagon.
Water for the furnaces was abstracted from the Keer. It was filtered and pumped to the two ponds across on the East side of the Lancaster to Carlisle main line. There was a cold pond (fresh filtered water for cooling the furnaces) and a recirculating or cooling pond. The boilers and blower house, and latterly the steelworks would also be part of the system. The site water system would see several changes through time.
Phase 2 1869 to around 1900
16 hot blast pipe stoves were installed to a patented John Player design that was already in service in the North East. It was shortly after this that the No 4, 5, and 6 furnaces were built (together with a second lift). The ironworks most productive period was between 1871 and 1874 albeit they may never have had all 6 furnaces in blast concurrently.
Against a background of an unpredictable market, the expectation was an increasing demand for steel and Carnforth invested in Bessemer steelmaking plant which came on stream in 1874. It saw the installation of two 6 ton converters, cupola furnaces, plate and rail rolling mills and a second tall chimney. By 1876 the market again slumped and only one furnace was in blast.
In 1880 the Player pipe stoves servicing the 1, 2, and 3 furnaces were removed, replaced with five Ford and Mancur regenerative Hot Blast Stoves (see image below). These employed a new method of working, blast furnace gas was used to heat a refractory core within the stove which raised the temperature of air before it was blown in to the furnace. It saved time, saved energy, and helped raise output, allowing the furnaces to be worked harder. After 1880 the works supplemented its water intake from the local waterworks company and in 1882 two steam driven direct acting blowing engines replaced the original pair of beam engines.
By 1890 market conditions meant the ironworks ran with only one furnace in blast for extended periods. Meanwhile America was introducing major innovations, supplying increasing volumes to its home market, and competing successfully with British manufacturers.
By 1898 steelmaking was finished and the plant was dismantled leaving ironmaking in the blast furnaces as the main process. It appears that the steelmaking venture was too late to the party. Rapid advances in the industry meant that Bessemer steelmaking was already losing out to Open Hearth steelmaking which could accommodate lower quality ores available in greater quantities in other parts of the country.
Here are two versions of the same image, the first is reproduced in original condition for clarity and the second has been highlighted to draw attention to points of interest:
1,2,3 are the original three blast furnaces blown in in 1866, and now feature the 5 Ford and Mancur Regenerative hot blast stoves marked s. 4, 5, and 6, still have their original Player pipe stoves. At this time they were likely out of use (being less efficient).
L denotes the two enclosed hoists. They appear to be brick built, with plate hoods on top. Inside was a lift arrangement to transport laden barrows up to the charging platform and return empties to the bunkers for refilling.
b is the blower house, capped with a water tank. This provided a cold air blast to the stoves (3 per furnace) which heated the blast.
WCML is the London and North Western Railway Company's West Coast Main Line to Scotland.
C is above two Coke wagons on the high line which had two parallel tracks. Coke is a very lightweight, fragile commodity. Coke wagons were distinguished by having tall sides and high volume capacity and built with side or bottom doors for emptying. They are positioned above the Coke bunkers which are different in design and construction to the limestone and iron ore bunkers. The coke bunkers are distinguished by squared off, vertical stone wall dividers, as distinct from the walls of the other bunkers which had sloped ends. The sides are sheathed with timber planks but the bottom third appears to be a ventilated chequer brickwork wall, possibly to help avoid fires. During transport and handling, Coke would disintegrate in to smaller and smaller pieces called coke breeze. It was detrimental to good blast furnace operation because it inhibited the free passage of reducing gases through the burden. The coke would usually be screened either manually or mechanically to take out coke breeze.
O Twelve iron ore hopper wagons with steel bodies. They are short wheelbase with spoked wheels, sprung buffers, single side brake gear and the ends have an elliptical shape. They had bottom opening doors and were owned by the company. The Furness Railway had a fleet of similar wagons, iron ore being a major commodity. The hoppers were smaller than coke and open wagons because iron ore is a very dense and heavy material to transport. It is not unusual to see images of coke wagons full to overflowing, but not so with iron ore hoppers.
The high line starts to the right from ground level as a fill or earth ramp, then there is a section between stone walls supported by trestle work then three bunkers. The first of these three stores a material darker and coarser in texture than the other two, possibly iron ore then the second and third, limestone. The two bunkers between the coke bunkers are stocked likewise.
Beneath W are two lines of one, and two, plank open wagons on the exchange sidings used for transporting pig iron. They are probably empty L&NWR company wagons and waiting to be taken in to the works for loading.
The tall chimney between 4 and 5 is in the rear and part of the short lived steelworks plant. The ponds are visible in the foreground.
In August 1874, the Iron and Steel Institute spent several days touring local industry. They visited Carnforth and we are fortunate that the visit was comprehensively reported in "Engineering" September 4 1874 Volume 18. Click to reveal
The Carnforth Hematite Iron Works are situated at Carnforth Junction, where the Furness Railway joins the London and North-Western system. ‘They include a remarkably fine blast-furnace plant erected from the designs of the present engineer, Mr. Edward Barton, while there is besides a Bessemer plant and rail mill in course of completion. The blast furnaces are six in number, and are 65 ft. high, the largest being 20ft. in diameter at the boshes. They are all iron-cased, and the tops are closed, (1) being fitted with the ordinary bell and hopper. The blast-heating stoves are all cast-iron pipe stoves, and they and the boilers are all fired by gas.
The furnaces are all placed in one row, and connected by top galleries, the whole set being served by one hoist worked by a small winding engine (2). There are three blast heating stoves, namely, one at each side and one at the back of each furnace, the latter being placed sufficiently far apart to give ample room for circulation about them in all directions. Behind the furnaces is a row of bunkers for coke and ore, these bunkers being supplied from a railway running over their tops. At present, four only of the furnaces are in blast, but during our visit another was being dried by a jet of gas drawn from the gas main of an adjacent furnace - a very neat way of getting the necessary heat. At the end of the row of furnaces is a very fine engine house, or rather a pair of houses connected with each other, these houses containing six blowing engines, namely four for the blast furnaces, and a pair for the Bessemer plant. Of the blast furnace engines, the older are a pair of beam engines with a pair of 100 inch cylinders, 54 inch (3) steam cylinders and 10 ft stroke, while the other two are vertical engines by Messrs. Galloway of Manchester with 84 inch blowing cylinders. In these engines the blowing cylinder is overhead, and the steam cylinder below the level of the crankshaft, the steam piston having a plunger on the upper side for the purpose of reducing the area exposed to the steam during the downstroke, when the weight of the moving parts assists the steam pressure. The piston rod carries between the two cylinders a crosshead, having a connecting rod bearing out of line with the piston rod, the connecting rod swinging close to, but on one side of the piston rod. At its lower end, the connecting rod takes hold of an overhung crank on the flywheel shaft, the latter having one bearing on the engine frame and one in the engine room wall. The valves of the blowing cylinder are disposed on the upper and lower sides of annular chambers which surround the blowing cylinder at its upper and lower ends, and they afford a large air way and work almost noiselessly. The steam cylinder is fitted with a piston slide valve, this valve having its spindle provided with a kind of ratchet arrangement, so contrived that each stroke the valve is moved round in its cylinder a small fraction of a revolution. A similar arrangement is adopted in the Bessemer blowing engines and in the rail mill engines, and it appears to be an excellent one, and calculated to insure even wear. The Bessemer blowing engines are also by Messrs. Galloway and are similar to those above described, except that they have, of course, smaller blowing cylinders, and that the two engines are coupled, the flywheel being between them. The Bessemer engines also have their blowing cylinders fitted with piston valves worked by an eccentric. Both the blast furnace and the Bessemer engines by Messrs. Galloway are of very good substantial design and excellent workmanship.
The Bessemer plant at Carnforth is at present, in an incomplete state. One pair of five ton converters is mounted, together with their ingots, cranes, ladle crane, etc., but the rail mill, which is a reversing mill on the Ramsbottom system, is only partially erected, and the rail saw, straightening machines, etc., are not yet in place. The horizontal engines for the reversing mill are, however, fixed, and the other work is in hand. The two converters already mounted were formerly at Mr. Bessemer’s works at East Greenwich, and there is nothing special in their arrangement. The ladle crane is however provided at the ladle end with a crane jib, which reaches over the ladle, and which can be used for lifting off the converter bottoms. The top of this jib is connected by a tie rod with the centre of the ladle crane, and by means of an adjusting screw on this tie rod, the overhang of the jib can be controlled. At the straight, or converter side of the jib, the latter communicates by arched openings with a chamber beneath the platform on which the cupolas are mounted. These latter are all Woodward’s steam-jet cupolas, there being two large ones for pig, and two smaller ones for spiegel. (4) The runners from the cupolas to the converters are a series of cast iron troughs, a very neat arrangement. It is intended, we understand, to experiment at Carnforth on the use of white iron in the Bessemer converters, arrangements being, we believe, about to be made for the injection of a certain percentage of carbon with the blast. This plan has already been successfully used in Austria, and it will be interesting to know it will answer in this country. (5) We may add that a pit has been prepared at Carnforth for the erection of a second pair of converters when necessary.
NOTES
(1) This style of early furnace is sometimes described as open topped, because they look open topped, but they had a single bell which was closed most of the time, albeit they were not always gas tight.
(2) Only one hoist reported in service, yet two in the pictures. However, there were only 4 furnaces in blast at the time of the visit.
(3) Originally reported as 45 inch steam cylinders. This is likely a typographic error, although it is possible the cylinders were enlarged some time after installation.
(4) Cupolas were upright furnaces used to melt iron. Unlike at other works, Carnforth had no facility to transfer molten iron to the converters. The iron was cast as pigs and then remelted. Costly and inefficient. Spiegel is short for Spiegeleisen, a ferro manganese alloy high in manganese which was desirable for Bessemer steelmaking. The major constituent would still be regular pig iron.
(5) This is cutting edge steelmaking. We would never have known Carnforth were doing this had it not been in the visit report. 18 years after Bessemer's process was born, and still evolving.
For comparison, the blast furnaces at Skinningrove on the East coast share many common features with the Carnforth furnaces and show what the pig beds might have looked like. This arrangement of furnaces, stoves, lifts and adjacent pig beds was very common at the time.
The East Cleveland Image Archive have some superb images depicting the operation of the Skinningrove pig beds and is well worth visiting.
Google has digitized Hunt's Mineral statistics for 1879 here. (Easier to view in pdf format). Hunt recorded that Carnforth had 6 blast furnaces and that 4 were in blast for part of the year, (2) that the works did not have any puddling furnaces but they had 3 rolling mills and they employed regenerative gas heating furnaces ( for heating the steel ingots before rolling). Carnforth had 2 Bessemer converters of 6 tons capacity.
6 tons is typical of contemporary converters, Moss Bay had 3 vessels of 8 tons capacity which were ultimately replaced by 2 of 25 tons capacity until closure in 1974. Tiny in comparison to today's steelmaking vessels.
Notes
(1) The Bridge stocker(s) may be a local term for the crew responsible for loading the furnace with raw materials. In other places they were called furnace chargers or fillers.Notes
(2) Up from one furnace only in blast in 1876.
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