WW1 BRITISH IMPACT FUZE (FUSE) No 13 Mk 5 AND COLLAR or PLUG

Impact Fuse No13 Mk5 and collar or plug for unknown projectile, it is not certain if the two objects go together. The No13 Fuze was a direct action impact type in use in 1915. Used with heavy common Lyddite shells. The charge will only detonate on impact, and there is no safety feature other than pins removed before installing into the breach.

Your comments:

• The item on the left is actually two items firstly an outer collar, or adaptor used in the 2 inch gauge hole in the nose of a High Explosive shell to reduce the size of the opening to 1.5 inch to allow for the fitting of either a plug, which is currently inside or if the plug is removed it can be replaced by the no. 13 fuze.
  .......... Jo Lawler, Southampton, 18th of May 2015
  
  
• The item on the left looks a bit like the early black powder time fuses. If the top part is a lead lid, and the bottom has a lid of the same material, then that's probably what it is. Before firing, the top lid would be removed exposing the black powder fuse. The fuse cut to length then pressed back into the holder. The acceleration would tare the bottom lid off exposing the time fuse to the internal powder charge. That lid was an extra safety separating the fuse and the powder charge.
  Acceleration during the launch would press the conical time fuse securing it further, and the gas ring of the shell had grooves allowing some of the burning BP drive charge to pass it igniting the fuse.
  .......... Anders Bjork, Umea, Sweden, 11th of April 2015
  
  
• The safety feature for the fuze is the cap (secured by the securing pins). The cap prevents the hammer being struck accidentally during handling.
  
  Difficult to tell from your picture, but I think the other item may be a 'Plug, Fuze Hole'
  
  Regards
  
  Jim
  .......... Jim reid, Salisbury Wilts, 30th of November 2010
  
  

A0437