Unusual bakelite practice bomb

[Burney Davis]

Could anyone provide details of this practice bomb please. Very light weight and measures 7.5cm x 24.5cm. The wooden part of the fins could be a replacement but the fins themselves are original. I suspect it is interwar period. There are at least two of these in existence.

 

[Burney Davis]

Just bumping this thread.

 

[ThomasP]

Weight? Empty or filled with sand, etc?

 

[Burney Davis]

Weight? Empty or filled with sand, etc?

As it is it weighs 0.87 lbs, so very light. It is empty.

 

[ThomasP]

Without knowing what the internal arrangement actually was (ie how much volume was available for the sand filling) the volume of the empty shell would allow a maximum of about 3 lbs of sand.

I based the volume of the shell on a scaled outline of the picture and converted to a 3D ovoid of the about the same cross section area, using Ø3" as the diameter and a minimum of 7.5" and a maximum of 11" as the length of the oval. This gives 35 to 52 in3 of sand. At about 0.057 lb/in3 density for the sand this gives 2.00 - 2.96 lbs.

So it is probably safe to figure the bomb weighed a minimum of about 3 lbs, and maybe upto 4 lbs when dropped - if the shell was totally filled with sand.

Another question, is the diameter actually 75mm, or is it closer to 76mm? If the diameter is ~76mm then I suspect it is British in origin as the British seemed to use the Ø3" for their practice bombs that I am familiar with.

Of course, without knowing the actually internal arrangements, the idea that it was filled with sand is speculation to a degree and therefore my calculation as to the weight could be totally wrong.

I assume there are no identifying markings on inside or outside of the shell?

 

[Burney Davis]

No marking on this. I'll see if I can get it open when I get a moment.