WW1 Transit caps ? What for?

[Millsman]

A friend has just brought some of these caps back from the Somme battlefield. They both have twist off type top. One is marked No.17 and the other No.44. The one marked No.44 has a number of vents in the top and small metal tab screwed on one side. The one marked No.17 is altogether much simpler.

Can anyone say what piece of kit they protected?

 

[Snufkin]

They are the safety caps of No.17 and No.44 percussion fuzes, removed before loading the shell into the breech. Often found in what were British RGA positions.

 

[Millsman]

Many thanks for that. I'd not seen these before and am not familiar with those fuzes (but will look them up). They were found on the Somme near a large pile heavy brass transport / transit plugs. So that again also fits with your answer.

 

[Millsman]

Following Snufkin's pointer I've found some nice illustrations in the 1915 Treatise on Ammunition. Worth sharing. The No. 44 isn't in the 1915 edition but the No. 13 shared the same cap.