tillergirl
Well-Known Member
Someone was asking about the rule of twelvths which I have always used.
Just to cope with ennui, I was musing through the Pilot's Guide for the River Thames and the Strait of Dover edited by Imray and Kettle, 1908 and it has the following:
"Generally, it may be assumed that, from Low Water to High Water (Springs and Neaps), the water rises one-sixteenth of the range in the first hour, three sixteenths of the range in the second hour; four sixteenths of the range in third hour; four sixteenths in the fourth hour; three sixteenths in the fifth hour and one sixteeenth in the last hour. And it falls from HW to LW in the same ratio."
Other useful items include:
"Trinity High Water Mark at London Bridge, as fixed by Act of Parliament in 1800, is 12.53 feet above Ordnance Datum, which in England is the mean-tide level at Liverpool taken as being 4.67 feet above the old dock sill. The mean tide level at London Bridge is 2.44 feet above Ordnance Datum". Or as Black Adder would say 'so something you can't measure very well is slightly higher than something else you can't measure very well'. And how high was the old dock sill at Liverpool anyway?
"In order to communicate that a vessel is on either of the undermentioned sands, the arranged signal is to be fired from the lightvessel or pile lighthosue and repeated until answered from an inner lightvessel or Coastguard station (are you paying attention Dick?) or by a signal from the life-boat on arriving at the vessel indicated.
Gunfleet and Cork Sands Two guns and two rockets every twenty seconds repeated every ten minutes
SW Long Sand One gun and one rocket every ten minutes
NE Long Sand Two guns and two rockets every five seconds repeated every ten minutes
Etc"
I think things are a bit simpler today!
Oh and 'Jenkin Swatchway' is where?
Just to cope with ennui, I was musing through the Pilot's Guide for the River Thames and the Strait of Dover edited by Imray and Kettle, 1908 and it has the following:
"Generally, it may be assumed that, from Low Water to High Water (Springs and Neaps), the water rises one-sixteenth of the range in the first hour, three sixteenths of the range in the second hour; four sixteenths of the range in third hour; four sixteenths in the fourth hour; three sixteenths in the fifth hour and one sixteeenth in the last hour. And it falls from HW to LW in the same ratio."
Other useful items include:
"Trinity High Water Mark at London Bridge, as fixed by Act of Parliament in 1800, is 12.53 feet above Ordnance Datum, which in England is the mean-tide level at Liverpool taken as being 4.67 feet above the old dock sill. The mean tide level at London Bridge is 2.44 feet above Ordnance Datum". Or as Black Adder would say 'so something you can't measure very well is slightly higher than something else you can't measure very well'. And how high was the old dock sill at Liverpool anyway?
"In order to communicate that a vessel is on either of the undermentioned sands, the arranged signal is to be fired from the lightvessel or pile lighthosue and repeated until answered from an inner lightvessel or Coastguard station (are you paying attention Dick?) or by a signal from the life-boat on arriving at the vessel indicated.
Gunfleet and Cork Sands Two guns and two rockets every twenty seconds repeated every ten minutes
SW Long Sand One gun and one rocket every ten minutes
NE Long Sand Two guns and two rockets every five seconds repeated every ten minutes
Etc"
I think things are a bit simpler today!
Oh and 'Jenkin Swatchway' is where?
)
