Classification of ship damage.

[Peter Clare]

Thought I would post this as I thought it might be of some use to someone other than myself. Its part of my ongoing research into Coastal Command. Not sure if the committee that drew this up could quite make up its mind.

RAF Coastal Command Classification of Merchant Ship damage August 1941.

Category I. Sunk or constructive loss.

(a) Must be seen actually to sink, blow up, or be burnt out.
(b) Enemy admission after air attack.
(c) Subsequent definite confirmatory reconnaissance, i.e. wreck of wreckage seen, crew in lifeboats etc.
(d) Hits by sufficient weight of bombs to class as constructional loss.

Category II. Seriously damaged.

(a) Beached.
(b) Well on fire.
(c) Abandoned.
(d) Reported well down by the stern, bad list etc, but not actually observed to sink.
(e) Hits by sufficient weight of bombs to cause serious damage.

Category III. Damaged.

(a) Seen to be hit, but not Sufficiently heavily enough to be assessed under II above

Category IV. No observed result, near misses, no claims.

(a) Unobserved results
(b) Near misses (to be assessed on their merits)
(c) Believed hit.

To assist in the allotment of results to one of the four categories mentioned above it was also found necessary to categorise the merchant vessels as follows:-

(i) Ships of 500 gross tons and below.
(ii) Ships of 501 to 2,000 tons
(iii) Ships of 2,001 to 4,000 tons.
(iv) Ships of 4,001 to 6,000 tons.
(v) Ships of 6,001 tons and above.


Regarding the numbers and types of bombs used it was considered that if a ship of 2,000 gross tons or below was hit in a vulnerable part by a 250lb bomb it could practically always be placed in Category I or II. If a ship of 2,000 / 4,000 gross tones was hit by 2x250lb bombs, this would also apply. A ship of 4,000 tons or over would have to be hit by three or more 250lb bombs before it could be placed in these categories. If 500lb bombs were used, these figures should be halved. On the other hand, they should probably be doubled for tankers, which owing to their construction, were not so susceptible to damage as ordinary merchant ships.

With regard to near misses, it was concluded that one of under 10 yards (with G.P. bombs) could usually be placed in Category III. There would of course, be occasions when the evidence enabled a near miss to be placed in Category II, but these would be exceptional. The fact that merchant vessels contained many cast iron fittings susceptible, to damage, was one reason why a near miss of ten yards with a G.P. bomb might well cause a fracture to some vital machinery. Near misses over 10 yards away, in the great majority of cases, would cause no damage.

Torpedo attacks should only be placed in Category I if the ship was seen to sink or subsequent evidence proved that it had sunk. If the ship was merely seen to be hit by a torpedo, it would be placed in Category II.