Waverley's original boiler was built by Rankin & Blackmore at their Eagle Foundry in Greenock and installed at the town’s Victoria Harbour in February 1947. It was originally a hand stoked coal-fired unit with six furnaces; three at either end. During the winter of 1956/57 it was converted to burn Bunker Oil by the installation of a Howden patented oil firing system.
Early during Waverley’s preservation career it became apparent that to give the steamer a long term future she would need to be re-boilered. Endless tube problems during the 1975 season had lead to re-tubing ahead of the 1976 season but further work was required by the end of the decade. To ensure the long term operation of Waverley the original boiler would need replacing.
In 1980, the decision was made to re-boiler Waverley to ensure she had a modern, reliable and economic boiler. An appeal was launched to help raise the funds.
Various options were considered before the contract to build a new boiler was awarded to Babcock Power Ltd (Shell boiler division) of Renfrew. Waverley’s original Scotch boiler required very gradual heating due to its age and was latterly given 3 days to warm through! Once steamed, pressure was not allowed to fall below 100lb/in2 at any time, necessitating a fireman on night duty to ‘flash up’ to full pressure as required.
The new boiler chosen for Waverley was a ‘special’ Babcock Steambloc TC50 adapted for marine use to meet Waverley’s rather unusual needs. The new burner equipment was supplied by H Saake Ltd who worked with the engineers of Babcock Power. The order was placed in July 1980, for delivery in early March 1981. The lighter weight of the new boiler resulted in Waverley floating a mean 2” higher in the water; with her paddle wheels at a more favourable immersion. The distribution of weight fore and aft now gave her a level trim with a beneficial effect on her steering.
On 6th March 1981 Waverley's funnels were removed. The aft one was first off followed by the forward funnel. The ship was then towed the short distance to the Stobcross Crane (Finnieston Crane) on 10th March where the old boiler was lifted out. The new Babcock boiler was then lowered into position a few days later.
The new Steambloc boiler could raise steam and start up from cold in 5 hours. Manning costs were reduced as only one fireman was required in the boiler room when the steamer was underway, this resulted in two less men being required in the engine room department. The Babcock succeeded in reducing costs as fuel consumption dropped by over 23% compared to the old boiler.
As it was proposed to equip the new boiler with spinning cup type burners, with all electric pumps fans and attendant control gear it was obvious a complete re-think of the generating capacity was necessary. Two Caterpillar generators were installed; both comprised a 3306 turbocharged engine, direct-coupled to an 110kW alternator. Each unit was water cooled and had its own heat exchanger and sea-pump. The contract for the project was awarded to Clyde Dock Engineering Ltd of Govan.
The Babcock Steambloc Boiler was then removed from Waverley after 19 years service at Great Yarmouth in 2000, during the first phase of Waverley's £7 Million Heritage Rebuild. Although it had an estimated residual life of 5 to 10 years at that time, it failed to find further service and was scrapped. It was replaced by two Thermax Boilers made by Cochran's of Annan.
On 10th May 2019 it was announced that Waverley was withdrawn from service and would need two new boilers. When Waverley's engine next turns it will using steam generated from the 5th and 6th boilers to have been installed in the ship.
Please consider making a donation to help 'Save The Waverley' and ensure that her boilers are replaced. Indeed encourage many others to match your donation to help save the last sea-going paddle steamer in the world!