2" HE Mortar

Discussion in 'Weapons, Technology & Equipment' started by Dafydd, Mar 17, 2019.

  1. Dafydd

    Dafydd Member

    Can anyone help me find how a 2" mortar is fired?
    As I understand it, there is a protective cap. Does this need to be unscrewed before it is fired. Alternatively how is a round made ready to fire?
    I'm researching a tragic accident when 3 boys were killed by one and I'm going through the newspaper account of the time.
  2. ClankyPencil

    ClankyPencil Senior Member

    See this link The Minute Book

    My understanding of it is that there is a propellant charge (similar to a shotgun cartridge) inside the fin part of the mortar.
    When it's dropped down the mortar tube and hits the bottom this is set off, causing the expanding gases out through the holes in fin and into the tube, and propelling the mortar towards target.

    The top end of the mortar had a fuze which is set off, and explodes the mortar when its the ground.

    These fuzes had safety caps are which had to be removed before firing. The fuze shown in the link is a DA161 and has a safety pin which would also need to be removed.
    I think the DA-161 fuze is what was used post WW2, and during WW2 DA-151 fuzes were likely used, and i'm not sure if they also had the safety pin feature or just relied on the safety cap.
    timuk likes this.
  3. Dafydd

    Dafydd Member

    I can't thank you enough for a thorough and helpful response. The link explained the firing mechanism of the mortar very well. I wonder if you have any thoughts on the following...
    In March 1945 a boy found an unexploded HE round on a practice mountain in N Wales and while he was tempering with it the day after, it exploded killing him and two innocent bystanders - one aged just 6. A witness in the coroner's inquiry stated: "He asked me to hold the bomb while he screwed off the fin. Ted then knocked off the cap and pulled out a screw with a pliers and a spring came out. Then he put a screwdriver in a hole in the bomb and white powder came out." Would this mean that Ted managed to take the inner cap off to get at those two spring loaded things and the white powder was the TNT?
    The inquiry also heard from the army and a major testified that about 2% were "blind" mortars - presumably ones that failed to explode? I this percentage right? Lastly, colour banding; I'm aware that there was a colour band to denote HE, LE, smoke, Illumination etc... but did they also have written signs to denote what the round was?
    The witness, by the way, had a providential escape. His mother called him in for his tea; he heard the explosion just as he sat down at the table.
    Many thanks for your help.
    timuk likes this.
  4. Tricky Dicky

    Tricky Dicky Don'tre member

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  5. timuk

    timuk Well-Known Member

  6. DannyM

    DannyM Member

    The trigger/firing lever is on the right hand side of the mortar.


    Trigger  2in mort  mer.jpg
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  7. ClankyPencil

    ClankyPencil Senior Member

    Timuk's link pretty much shows the typical markings.
    All i can add is that the Smk WP one, shown in the link, which is marked 'BT' (instead of M) indicates it's for a Bomb Thrower which were equipped on tanks. i think they were pretty much the same as the standard Smoke Mortar round except they had a 'clip' or similar device on the top of the round, so they could be extracted from the tube in case of mis-fires.
    timuk likes this.
  8. Smudger Jnr

    Smudger Jnr Our Man in Berlin

    Due to the short length of the barrel it was too dangerous to just drop the mortar down the tube to hit a firing pin.
    As already stated the 2" mortar was provided with a trigger to set off the mortar round.
    It was fired by pulling on a landyard attached to the side mechanism.

    timuk likes this.
  9. Dafydd

    Dafydd Member

    This is very helpful, thank you. Can you help with another query?
    During the coroner's inquiry a witness testified that the boy with the 2" HE mortar
    “knocked” the safety cap off the bomb and “pulled out a screw…and a spring came out…” It’s not clear whether the detent or the detonator spring came out. Which do you think it was? Secondly:
    "Then he put a screwdriver in a hole in the bomb and white powder came out."
    Would the white powder be the pentolite or the TNT charge?
    Many thanks if you can help.
  10. Tricky Dicky

    Tricky Dicky Don'tre member

    Hi Dee

    The answer to your question is beyond the realms of my particular knowlwedge envelope, but maybe there is someone on here that does know - if not you may need to call the experts - off the top of my head Bomb Disposal [as they may still deal with this type of ordnance], Royal Artillery Museum ??

  11. ClankyPencil

    ClankyPencil Senior Member

    Suggest you try posting your query on the 'British Ordnance Collectors Network' >>> Link
    Plenty of ex-bomb disposal type people on there, and collectors etc who dig these sorta things up and can probably identify fuse types, filling etc from the description given.
    timuk and Tricky Dicky like this.
  12. Dafydd

    Dafydd Member

    Thank you again for the help and I've done that.

    Would you know how the Army in WW2 dealt with unexploded mortars in training grounds? I've evidence that about 2% were 'blind' and didn't explode. A flag was placed in the 'vicinity' where it fell after they failed to find it in thick bracken/vegetation etc. Would they have called on specialists to deal with it or deal with it themselves?
  13. timuk

    timuk Well-Known Member

    If they bothered to do anything I presume the task would be given to Royal Engineer Sappers or Royal Ordnance Corps Ammunition Technical Officers trained in Bomb Disposal. However it doesn't look from this link that they looked for everything that had failed to explode and I don't think a 2" mortar bomb would be high up on the list.


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