Break-up Bombs

As a result of a question in another thread I thought I should add the reply to a new thread.

BREAK-UP BOMBS

The main type was the 8.5lb Bakelite practice bomb. It was designed for use at low altitude against armoured boats, submarines (live friendly ones), ASV target buoys and other targets where damage was undesirable. Upon detonation or break-up the filling would mix with the air to produce a white smoke or flame if used at night. Made in three parts most of this bomb was plastic or Bakelite and because of the low terminal velocity all breakup bombs could only be used at low altitude. They were in use throughout the war and although I have no date when it first came into use I suspect it was in the late 1920s or early 1930s. During the war the need for an even less damaging version caused the introduction of an 8lb breakup bomb. This special version of the breakup bomb was designed for low level training, up to 2,000ft, against airfield targets. It did not leave any debris that could damage aircraft tyres as the bombs were made with a body of an asbestos cement tube containing a glass flask filled with titanium tetrachloride. The flask was sealed by a cork and secured in the tube. There was no streamlining or fins and the bomb had no detonator-burster, merely relying on the impact to break it open.

There was also a break-up version of the 9lb AT (Anti-tank) bomb. This was made of earthenware and filled with a white powder, normally crushed plaster of Paris which would leave a tell tale white mark if it actually struck a vehicle. This was the safest of all the practice bombs as there was no burster or dangerous chemicals involved. It is doubtful this was used very much as the live version was considered to be both dangerous and ineffective, requiring suicidal delivery and withdrawn from service very quickly.

8.5lb Break-up bomb Smoke Mk I

Length 1ft 4in
Maximum diameter 3in
Weight (empty) 7lb (including added weight using lead antimony balls)
Weight of filling 1lb Titanium tetrachloride
Terminal velocity 784ft per sec

8.5lb Break-up bomb Smoke Mk II - Identical to the Mk I except for the striker mechanism which required an extension piece on the nose.

Length 1ft 7in (With nose extension)
Maximum diameter 3in
Weight (empty) 7lb (including added weight using lead antimony balls)
Weight of filling 1lb Titanium tetrachloride
Terminal velocity 784ft per sec

8.5lb Break-up bomb Flame Mk III

Length 1ft 7in
Maximum diameter 3in
Weight (empty) 7lb (including added weight using lead antimony balls)
Weight of filling 0.5lb Sodium Phosphide
Terminal velocity 784ft per sec

8lb Break-up Bomb Smoke Mk I

Length 16.5in
Maximum Diameter 4.2in
Volume of filling 300cc Titanium tetrachloride

I doubt if any asbestos cement bombs survive.