Astute observation

I really enjoyed your article about the Astute class submarine (Feature, 27 February). But who figured out what a family saloon car is per sq metre?

I really enjoyed your article about the Astute class submarine (

Feature

, 27 February).

But who figured out what a family saloon car is per sq metre?

That is so inaccurate. I always use unladen Audi A4/sq m, which works out at around 1,340kg/sq m. So this would mean the Astute will be able to withstand 52 atms, or 400 audis/sq m — 510m. I hope they stay away from the deep stuff.

Ian Higgins,
West Yorks

Thank you for your observations Mr Higgins. Family saloons may seem an odd unit of measurement, but as you will appreciate the actual pressure is something the MoD would like to keep a secret - officially.