The Steam Boat Association
The Steam Boat Association of Great Britain (SBA) was formed in 1971 to promote the enjoyment of steamboats and steam boating, and to represent the interests of steamboat owners.
Today, the SBA has around 1,000 members located in more than 20 countries throughout the world, who own over 400 working steam powered craft of various sizes and types.
The association’s 96-page quarterly journal The Funnel keeps members up to date on everything from products to events, boat builds, tips, meetings held around the UK and elsewhere, and much more.
They run seminars and can help with boiler design accreditation and testing to ensure that things are done properly in accordance with best contemporary practice.
■ steamboatassociation.co.uk
“It’s possible to buy a steam launch for as little as £6,000,” says Reverend Mark Rudall, Editor of The Funnel, the Steam Boat Association’s quarterly journal.
“It’s essential to give the boat a thorough check over to ensure that hull is in good condition, the engine is sound and the boiler has current certification or is likely to pass rigorous scrutiny by a new inspector who might not have seen it before.”
Boiler basics
The SBA has its own trading arm that provides professional boiler inspection services. As steam pressure can amount to some 17 Bar boiler safety has to be taken very seriously.
“As a rule of thumb, boats and boilers have fairly finite lives, but engines can go on almost indefinitely if maintained properly,” says Rudall.
“Boilers corrode if not well treated. Irregular hobby use with intermittent heating and cooling of the metal is less kind than the continuous use boilers received when in commercial service.”
For those who want to construct their own boat and power unit there are companies who produce plans for suitable hulls and steam engines; among the more popular are Stuart Turner engines, their 5A single cylinder engine and their 6A compound unit being good examples.
To the uninitiated a boiler can appear to be a dangerous smoking cauldron to be treated with great care, even suspicion. However, modern materials and production methods have made boiler technology a much safer science.
Steamboat boilers can be divided roughly into two categories: fire-tube and water-tube. Fire-tube designs can be both horizontal and vertical configuration whereby heat is transmitted to the water and steam space via tubes carrying the hot exhaust gasses to the funnel.
Water-tube designs tend to be lighter and carry less water. They also come in many forms. Steam is generated from water carried in tubes and drums strategically placed over the heat. Sometimes, the exhaust steam is piped back into feed-water for reuse in the boiler. Steam launch engines that condense in
this way run almost silently while ‘non condensed’ engines are called ‘puffers’ because of the soft ‘puff-puff’ of the exhaust beat up the funnel.
All boilers carry gauges to monitor the water level inside and the steam pressure available. Feed water for the boiler is fed by engine-driven pumps and/or injectors. Again, similar to steam locomotives.
Despite its greater weight the fire tube boiler has one major benefit: its relatively large quantity of water requires less attention and maintains pressure despite variations in the heat source making for greater relaxation on the part of the person controlling the boat’s engine.
Conversely, piping configurations in water tube boilers are usually arranged to encourage rapid circulation of the liquid, which in turn distributes the heat source evenly and allows for more rapid heat transfer for a given surface area.