SHF – John Oxley

Lifting the Boilers


Scotch-boiler-2colourThe John Oxley was fitted during her construction in 1927 with 2 Scotch wetback boilers, each weighing about 30 tons when empty. The weak state of the ship’s hull and floors supporting the boilers were of great concern for some time.

To repair the floors the boilers needed to be raised off the floors. They could not be lifted by crane from above without removing the superstructure. They could not be raised from the hull underneath due to its weak structural condition.

JO-boiler-sm.jpgIt was finally decided to build a supporting structure up from the dock with a saddle supported by struts through the hull. Thereby relieving the hull from the weight to do the repairs.

Load bearing girders were placed on the dock beneath each of the boilers. Struts were arranged at each end of each boiler whereby a hydraulic ram could raise the struts with the temporary plate saddle from the supporting structure on the dock. (See diagram below.)

After long deliberations, the boilers were lifted off their stools without much effort in September 2005. Each end of the boiler was raised about 25 mm in turn and 20 mm of packing plates inserted. The ram was lowered till the weight was taken on the packing plates and the ram could be taken away for use on the other side of the same boiler. The same sequence was followed on the second boiler.

After the repairs, the process is reversed with the rams raising each end of the boilers slightly to remove the packing plates and then lowering the boilers till they rest on the restored saddles and floors.