99029 Confusion with Orders

Confusion with Orders
Report No. 99029

Mars 99010 gave an account of potential confusion with orders appertaining to the use of the words "both" and "port" in relation to twin screw ships. I too have had a similar experience in recent months during a training exercise for OOW and ship handling with some of our Naval cadets. Happily we were operating offshore in a controlled situation but the potential for confusion hit home very quickly and was appreciated by the more experienced officers who were on the bridge at the time.

The ship in question gives a predetermined 250 revolutions when the order "Slow Ahead" is given. This is equivalent to 9 knots on two engines or about 5 knots when using only one engine. The physical surge ahead is quite dramatic and if the actual engine order passed by the OOW is mis-heard by the rating operating the engine levers, the result could be horrendous, particularly when approaching or leaving a berth or when manoeuvring in company.

Our standing order procedure in relation to operating in twin screw ships is in accordance with the Admiralty Manual of Seamanship Volume 1. The underlying principle is that, to avoid phonetic errors, and as a means of standardisation, the word 'engines' is always used in conjunction with the word 'both', but on no other occasion. For example "Slow Ahead both engines" but "Slow Ahead port/starboard". The order is then repeated word for word by the Quartermaster and reported to the OOW when the required movement has been carried out on the engine levers and registered on the shaft revolution repeater.