Wrong-Way Warning Switch. By Andy Selfe
In conversation with my cousin John Sherwin, one time Mate on Steam Tugs T H Watermeyer (1939) and R B Waterston (1954) in the late ‘70s. He said there had been some spectacular accidents caused by the Engineer reacting to the Speed instruction on the Engine Room Telegraph, but not noticing that the direction had been changed!
Much argument generally ensued; claims and counter claims as to who was at fault. I asked John why the Wrong Way Warning didn’t go off. He was unaware of this device, but when I showed the picture below, he agreed to find out.
From closer up, the chains can be seen:
The chain can be made out coming from the wheelhouse above, under a sprocket then to the right, through the Switch, then out of the Switch to the left, over another sprocket and down again to the Engine Room Telegraph directly below.
On the engine is the switch which senses whether the engine itself is set for Ahead or Astern:
If one is selected for Ahead and the other for Astern, an alarm should go off. John replied: “Your interesting photos below came through so huge I can't view or print them in current form. Could you try sending them again as attachments to an e-mail; I have a buddy here who I'm sure will identify your chains and 'wrong-way' notices if he can view the whole picture.”
Soon he replied: “Got my guru here this morning, and, yes, the 'wrong way' alarm did work! The extra chain also came from the telegraph, and told the silver box that the command was ahead or astern. The silver box in turn told the alarm on the engine. If the operator moved the ahead/astern control lever to the wrong direction, the alarm would sound.
“He reckons the big twin-screw tugs also had alarms, though we got our share of 'wrong moves' over the years! Of course, each engine (two on the large tugs) had 2 levers, 'ahead/astern' and steam pressure, so must have got quite exciting down there when we were throwing the telegraphs from full-ahead to full- astern several times per minute! The idea was to put the steam pressure to zero, choose ahead or astern on the direction lever, then feed in the steam pressure according to how much was asked for from the bridge. The 'cowboy' engineers never closed the steam, simply whacked the reverse lever from ahead to astern and vice versa! Must have been a lot of stress on equipment, but we loved it, because we got the power that much quicker.
“Hope all this is helpful in your quest for knowledge on how the old bangers were used.”
One should remember that in a normal sea-going vessel, direction changes happened seldom. However on a tug, several times a minute would not be unusual.
I vividly remember going out with John one day, his Skipper being Captain ‘Two-Can’ Dan Heywood. They tied the tug securely to the much larger trawler ‘Storesse’ (pictured below) which was tied up facing inwards in the Alfred Basin. Using only verbal commands to the helmsman and operating the two Engine Telegraphs himself, Captain Dan pulled the larger vessel off the quay, turned the two vessels 180 degrees in their own length, then went out of the basin between the Clock Tower and the Old Port Offices without touching sides (there was a clearance of a few feet each side) and out into Victoria Basin, where there’s supposed to be a strong cross-current at the mouth.
One can only imagine how many times those Telegraphs worked!
John says another source of argument came from lack of steam pressure at the critical moment. Just when full power was needed, the pressure would be low! To prevent any argument, a pressure graph recorder was fitted in the Chief Engineer’s accommodation. Strangely, this device seemed mostly to be out of action!
20th March 2011