Gyros - used in WW2 era?

[Gerard Peels]

Dear all

In order to determine the current position submarines probably used gyros. As on board electronics were not as much advanced as they are nowadays-maybe not even existant- could anyone provide some info on how courses were kept underwater?

Thanks

Gerard

[historydavid]

On submarines, and surface ships, the navigator took a sextant reading from the stars each day, and after making allowances for the wind and tide he could calculate their present position.

From that point, all courses and speeds were plotted by the navigator on a paper chart, so that their position could be determined at any time.

However, things started to get a bit hairy if it wasn't possible to take a star reading because the sky was obscured by cloud, something that could happen for several days in the Atlantic in winter.

The paper chart continued to be updated for course and speed changes and allowances for wind and tide and the assumed position plotted. Because the actual position could not be checked it was known as dead reckoning.

Good navigators would end up with only a small error in the dead reckoning position when it was eventually checked.

[Gerard Peels]

Hello David

Further to your reply, would you have any idea how drift as a consequence of currents was compensated for?

As a diver I have encountered situations where depending on the depth the current had even a total opposite direction. The dive was like a merry go round....

Cheers

Gerard

[historydavid]

Gerard, the simple answer is no, but I would guess that a fair amount of information was available to submariners regarding currents in various places in the world and they would use this to make an allowance when determining their position.

[Harley]

Just for the record, the Royal Navy had been using first Anschutz then Sperry Gyrocompasses since before the First World War.

'Afraid my knowledge of navigation, least of all submarine navigation, is woefully poor.

Harley