![]() For slow speeds the two main storage batteries are normally connected in parallel, and for high speed switched to series-thus doubling the voltage and halving the current for any given power requirement. Three thousand amperes to each of S-16’s two propeller shafts, six thousand total out of the main storage batteries, is a high rate of discharge in any league. Here’s what he wrote about a training attack on a S-class American boat: In making an attack they connected the batteries in series. My question is, if you wanted to keep the battery discharge rate at a minimum, wouldn’t you always keep the batteries in series?Įdward Beach in his book Run Silent, Run Deep said American subs did the same thing in WW2, only they just used the terms series and parallel. When attacking, the batteries would be grouped-up (in series). When speed wasn’t needed the batteries would be grouped-down (paralleled). Group-down meant connecting them in parallel. Group-up meant putting the boat’s two batteries in series. The British used the terms “group up” and “group down”. ![]() Note that when allocating fresh water, the batteries were a higher priority than the crew.Īnother question I have about balancing electrical power needs on a WW1-era sub: ![]() It was a complex mix of charge rate, time, temperature, voltage, and battery gassing called TVG - temperature/voltage/gassing which took many hours after completing a normal charge. ![]() We used to do long overnighters “doing an equalizer” to restore each cell in the battery to equal voltage and charge. Engineers and electricians spend a large part of their days and nights tending the batteries. There are charts that show specific gravity vs charge corrected for temperature.īattery maintenance on a diesel submarine is a very critical task. Discharging below about 1.150 or less than about 30 percent capacity is unhealthy for the cells. A lead acid battery uses sulfuric acid and water as an electrolyte, a fully charged battery will have a specific gravity of 1.256, a deeply discharged battery will be somewhere at or below around 1.100. It is small but it really gets the message across.īack to the batteries, most would speak 1250 rather than 1 decimal 250 when talking to another crewman. If we are ever allowed to travel again, plan a visit to the he Royal Navy Submarine Museum at Gosport. Sea Wolves - The extraordinary story of Britain’s WW2 submarines It deals a bit more with the personalities than the technical side but is a great read. If you are interested in British submarine history in WW2, this book is outstanding. Here in all its analog glory is a portion of the main switchboard on one of these boats: To test for leaks they just charged the interior with compressed air, and if the pressure didn’t drop they were good to go! They didn’t even have Christmas-tree indicator panels. ![]() Part of the attraction it is that the systems on these early boats are, for the most part, easy to understand. Sometimes the skippers seem more like fighter pilots than boat skippers. Part of it is the amazing battles they got into. Each cell in a submarine battery produces from 1.06 volts when fully discharged, to 2.75 volts at the optimum output, so connecting the 126 cells in each battery in series gives a usable output of from about 210 to 350 volts… submarine battery systems:Īmerican fleet submarines had two batteries, each composed of 126 cells. Other than this I haven’t found much on British WW1 sub battery systems. So if it was a 120-volt system, why did the voltmeters register the volts as 12-ish? Just because? Or was it a function of the way the cells were wired/grouped? The same book says the cells were 2.5 volts. Underfoot as in the after compartment, was the great hundred-and-twenty volt battery which fed the hungry motors, 'We’ll carry on on the series switch till five o’clock, we’ll be in 12 fathoms then, and sit on the bottom till dark. How’s the battery?’ ’ 11.85 and 11.81, sir,’ came the voice of the L.T.O., bending over the pilot-cell. How’s the battery?’ ’ 12.10 and 12.06, sir,’ answered Seagrave. My question is, why would the voltmeters read in the 12-11 volts range, when the batteries operated at 120-volts? I found a book that has the following passage: A question for any fans of WW1-vintage British E-class subs (operated from 1912 to 1922): ![]()
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