A unique "fix" !?

Hugh Ferguson
2nd June 2009, 21:22
Sometime in 1948 we arrived, somewhere off Hong Kong, in the old coal burning Elpenor in dense fog and anchored awaiting a clearance-no radar and no gyro.
Waglan Lt. had a cannon fog signal and it wasn't very long before the stand-bye man, Jimmy Newall, reported that he thought he had heard a distant explosion. I,(3rd mate) and Jimmy then gave our attention to where he thought he had heard the sound coming from, and sure enough, there came another explosion accompanied this time by the just visible flash of the cannon. This was enough to get the old man up to decide what could be done about it. He quickly came up with the thought that if somebody knew the speed of sound we could get a "fix". So, word went around the ship that if anyone knew the speed of sound he should report to the bridge. Only one came forward and that was Tommy Boylan, chief R.O.. He told us it was 700 ft/sec.(or was it yards). I was dispatched to the standard compass for a bearing and then to the chronometers, and Jimmy and the old man gave their total concentration to spotting the flash yet again. They both hollered at exactly the same time and I counted the seconds to the bang-we'd got our fix! (How strange that the powerful Waglan light could not be seen but the reddish flash of the cannon could).

makko
3rd June 2009, 02:05
We had a most enjoyable maths class in Mosslands Comp (the old Wallasey Tech) when they were doing a survey of one of the IOM vessels in Bidston dock. We could see the steam from the horn but it was several seconds until we heard the sound! We worked out that sound travelled at about 340 m/s. Hands on physics, you cannot beat it!
Rgds.
Dave

Ian6
3rd June 2009, 12:56
Same general location as Hugh's 'fix' but a dozen years later in P&O's 'Canton'. We picked up the pilot in dense fog and commenced our entry to HK very gingerly. Unlike Blue Flue we did have radar but I guess the pilot was an old BF hand. Any way he never looked nor asked for info from the radar but sounded the whistle more frequently than the rules required, listening to the echoes coming back on each side from the cliffs. If they arrived together we were in the middle of the channel otherwise he adjusted to achieve that. A less welcome and less frequent 'fix' came from departing aircraft from the old Kai Tak airport passing overhead, unseen but definitely heard.

Low tech but it worked a treat.

Ian

Hugh Ferguson
3rd June 2009, 19:09
Extraordinary port was Hong Kong. I called there 24 times and noticed on more than one occasion that despite the approaches being, sometimes, in dense fog, as you passed Lye Mun and entered the harbour, it cleared.
Did you, Ian, ever notice that?