Fairbairn steam crane

The Fairburn steam crane is a type of harbourside crane of an 'improved design', patented in 1850 by Sir William Fairbairn.

The crane's innovation was in the use of a curved jib, made of riveted wrought iron platework to form a square-section box girder. This could reach further into the hold of a ship, clear of the deep gunwales alongside the quay.

A typical size for these cranes would be able to lift 35 tons at a radius of convert|35|ft. They were powered by self-contained steam engines, with both boiler and engine mounted on-board the crane.

William Fairbairn & Sons of Manchester built a number of these cranes and also licensed the design to other makers.

Bristol

The only surviving Fairbairn steam crane is in Bristol, on the quayside at the site of the former Bristol Industrial Museum.

Construction

In the 1870s, Bristol Docks was going through a period of expansion. Iron-hulled ships were becoming larger, cargoes heavier, and there had already been investment in building a railway line along the harbour quay. Crane capacity was limited though – none of the harbour's 17 cranes being able to lift more than 3 tons.

Accordingly a more powerful steam crane was ordered, to be capable of lifting 35 tons and loading it directly onto a railway wagon. This was ordered from local makers Stothert & Pitt in 1875, although to the Fairbairn pattern. In August 1878 the crane had been completed and tested, at a cost of £3,600 for the machinery, plus the masonry foundations.

The jib has a radius (reach) of convert|35|ft and a height of convert|40|ft. The crane weighs 120 tons. A vertical boiler inside the cab operates at 100 psi and supplies two twin-cylinder steam engines: one for slewing (turning) the crane, a larger one for winding the lifting chain. The winding drums can be driven by their gearing at four different speeds. To stop the crane toppling sideways, it is anchored by a tubular iron column running down into a well convert|15|ft below the crane. Roller bearings beneath the cab carry the weight and a plain bearing at the foot of the well resists tipping loads. Water for the boiler is supplied by a pump, which originally drew water straight from the dock and is also used for draining the well.

The cab of the crane is also of iron, with small-paned windows. Some time around 1900 the winding drums and their gears were enclosed in a further box on the roof. These window frames are decorated with small roses case into the junctions of the glazing bars.cite book
title=Fairbairn Steam Crane 1876
publisher=City of Bristol Museum & Art Gallery
work=Information Sheet 1
edition=2nd ed.]

In service

Although mechanically capable, the crane was not a great success commercially. In 1890 it was only used for 16 days of the year, for a profit of just 11"s." 6"d." Ships had increased in size by this time and the jib could no longer reach far enough to remove engines or boilers for repair work. It was even considered raising the crane up on a stone tower, as for the smaller crane at Canons Marsh opposite, to increase the lift height.

In 1892, hydraulic machinery, including cranes, appeared in the docks. These used a powerful central power supply and could transfer cargoes more quickly. The crane was required less and less often, although as the heaviest lift crane in the harbour it was still valuable. For a whole year between April 1905 and April 1906 the crane went unused. In 1906 electric cranes appeared too. From 1903 to 1909 it made a total of 143 lifts.

During World War Two the crane's heavy capacity was still useful. Around D-Day it spent two months working every day, lifting damaged landing craft onto the quayside for repair.

Today

The crane is still operational and is regularly steamed.

With the gradual closure of the City Docks, in 1973 the crane was passed to Bristol City Museum. In 1976 it was made a Scheduled Ancient Monument, as the last surviving Fairbairn crane. From 1988, it was restored to operational condition as part of the Bristol Industrial Museum. The crane operates on special museum days, such as bank holidays and the Harbour Festival.

External links

References