The Cast House Floor

Identical images of the base of one of the Carnforth furnaces, date unknown, but probably late in the lifetime of the works.

A is the Bustle pipe supplying hot blast to the tuyeres (B). It doesn't surround the entire furnace but is a horse shoe shape. It is unusual, being rectangular in cross section.

B is the water cooled tuyere directing hot blast in to the furnace hearth. There are four sets of cooling pipes visible suggesting four tuyeres in this front half and another four in the rear. A total of 8. They were a consumable assembly, being closest to the molten slag and iron. They were fixed in place with a set of gib & cotters and when necessary, the furnace would be taken off blast and the tuyeres exchanged.

C is a control valve on the base of a nearby hot blast stove.

D is the incoming cooling water main surrounding the furnace. It is difficult to see if the large bore pipes E are connected to the tuyeres or to bosh coolers (or both). The smaller bore pipes are the return flow of hot water to the open topped, rectangular trough F surrounding the furnace (directly below the water main). It may appear crude to direct the return flow to an open trough but it was a very simple and effective way to check water flow and was still in use at Workington's blast furnace until closure around 1980.

G is the slag notch from where slag, floating on top of the iron, was tapped at the start of every cast. It is higher than the iron tap hole. The slag runner H is a sand lined "Y" shaped trough directing the molten slag to slag ladles below.

J is a shut plate for a sow. It is a U shaped mild steel plate bolted to a steel bar. It was jammed in to the sow during tapping in order to control or divert the flow of molten iron. The end of the bar has a 90 degree bend and a short length to allow greater control and to assist extraction.

K is the hot metal runner.

The slag notch and the iron notch were plugged with clay while the furnace was in blast. The furnace would be tapped, say every 6 hours. First the slag notch plug was broken using long handled tools and the slag decanted. Then the iron notch plug would be broken and the molten iron guided to the sand filled pig beds.

Later, electric or pneumatic machines were developed to replace the manual work, making the environment safer and speeding the process.

The cast house floor was significantly higher than ground level. The slag was directed to slag ladles positioned on adjacent railtracks. The pig iron was directed to the extensive sand filled pig beds and allowed to cool. All the pigs had to be recovered, separated, and removed, an entirely new network of troughs rebuilt in sand before the next furnace cast.

There are ten men in the picture. Its interesting to take a closer look at the crew, back row first, left to right:

1. Foreman B. Smith. He is dressed a bit smarter and with too many layers of clothing to be spending a lot of time beside scorching hot metal. *John Easter Roberts in his 1977 book "Old Carnforth" named some of these gentlemen.

2. J. Roper with short sleeved shirt and grasping a shovel. The molten slag and the iron flowed out of the furnace in sand filled troughs. The shovel was an obvious tool for labouring with sand.

3. J Armer has leg protection, a long sleeved shirt and a mutton cloth sweat cloth around his neck. That suggest he is a senior furnaceman and working close to hot metal.

4. As 2. (might be related !).

5. A second senior furnacemen or a labourer.

6. As 2. He is holding a long bar with a ring on the end (handle). The business end is hidden but it could have an enlarged conical point, making it a slag bot, or it could have an L shaped end making it a hook, or a flat plate at 90 degrees making it a rake.

7. This is the senior most senior furnaceman. Older, grasping two spanners and a shut plate . His arms are completely covered suggesting he works more closely with molten iron. We was in charge.

8. I think this is the second in command. He is wearing a sweat cloth around his neck and he is holding an interesting tool. It has a delta shaped piece at one end and a larger diameter section at the other, with possibly a pipe or hose attached. I have seen long bars with hooked ends used as a tuyere or cooler snatcher. I think that is similar to a manhole cover lifting tool and it could be a pneumatic device for extracting "things" More research needed!

9. (George Jones) and 10. Probably junior labourers.

After every cast, there would be a lot of cleaning up to do. Disposing of residual iron and slag, rebuilding the sand runners, and repositioning gates etc.