Type 4 Ceramic Grenades

Type 4 Ceramic Grenade

Grenades have long been used in warfare across the world. However, their manufacture requires certain industrial materials and production lines.

In the closing stages of WWII, strategic bombing had decimated Japanese industrial infrastructure, leading to the development of a last-ditch weapon: the Type 4 grenade.

The Type 4 is also known as the “ceramic grenade” because it was made of porcelain or terracotta. These were materials which could be found at the end of the war when more traditional grenade materials were in short supply.

The Imperial Japanese Navy Technical Bureau came up with the idea for this new weapon. It was easy to make and cheaper to produce than traditional grenades at the time. This new weapon was to be used by the general populace of the country in the event of an Allied invasion.

To mass produce these grenades, kilns which were normally used for Japanese pottery were forced into service. The grenades that were produced by the kilns were cruder than traditional shells but were still able to do their job. There was also a significant variation in color, size, and shape as each kiln created a different form of the weapon.

The average Type 4 grenade measured around 80mm in diameter although, as stated above, the size would vary depending on the kiln producing them. The grenades were generally unmarked and completely plain.

The kilns also made them in varying shades of tan and brown. There were some which were completely white, but they were in the minority. While the grenades were made from porcelain or terracotta, they were not left untreated. They were lightly glazed both inside and out.

Despite the materials being used, the grenade would only weigh about one pound (453g) making it easy for soldiers to throw or carry around.

As with many other grenades at the time, the Type 4 was a spherical shape. It also had a bottleneck which included a wood friction fuse. The grenades came with a separate scratch block lid and rubber covering on the top which needed to be removed before the grenade was activated.

When it came to using this weapon, soldiers had to act quickly. To ignite the grenade, the rubber covering would need to be removed, and the match compound lit. This was done with the scratch block and worked in a similar manner to a road flare.

Once the fuse was lit, there was no way to stop it without destroying the whole fuse. To ensure that there was enough time for the grenade to reach enemy fighters, there was a four to five-second delay. After this time, the lit fuse would come into contact with the explosive materials inside.

Many of the Type 4s had a lanyard which was used to carry and throw them. A US Army intelligence bulletin from March 1945 stated that these grenades were easy to throw. The bulletin also listed some of the potential drawbacks of this last-ditch weapon.

Other than the fact that the grenade had to be thrown as soon as it was lit, care also had to be taken to ensure that the shell would not hit any hard objects before reaching the intended target. Should this happen, the grenade would shatter and become useless.

Ceramic Grenade pile,
pic courtesy of Japan Bullet

The grenade was also viewed in the bulletin as a concussion weapon. The explosion resulted in a large blast, but little in ceramic fragmentation which caused the most damage. This could be due to the materials used to create the grenades.

The Type 4 grenade was not a real game-changer in the war, but it was an ingenious invention. It was supplied to the Volunteer Fighting Corps as well as reservist organizations. There are also accounts that large numbers of them were sent to the front line troops.

These grenades were used by the Japanese in both the Battle of Okinawa and the Battle of Iwo Jima.

From War History on-line.

Click on images to enlarge.

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Military Humor –

 

 

 

 

 

 

 

 

 

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Farewell Salutes –

Keith Andrews Toronto, CAN; RAF, WWII, pilot instructor

Kenneth Bailey – Easton, MD; US Navy, WWII & Korea, USS Sangamon, (Ret. 24 y.)

Earl Thomas Conley – Jamestown, OH; US Army / country singer

Kenneth Deal – Shreveport, LA; US Merchant Marines, WWII, Troop Transport / US Army 313th Engineers

Max Gaberseck – Coudersport, PA; US Marine Corps, Gulf War, Sgt. (Ret. 21 y.)

John Hooten – Joppa, AL; US Army Air Corps, WWII & Korea (Ret. 24 y.)

James Kounanis – Chicago, IL; US Army, WWII, PTO

Harold Poff – Roanoke, VA; US Army Air Corps, WWII, PTO, 221st Medical/11th Airborne Division

Eugene Richard “Butch” Skoch – East Meadow, NY; Vietnam, Pfc, KIA

Joan Whittow – Liverpool, ENG; British Army, WWII

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About GP Cox

Everett Smith served with the Headquarters Company, 187th Regiment, 11th A/B Division during WWII. This site is in tribute to my father, "Smitty." GPCox is a member of the 11th Airborne Association. Member # 4511 and extremely proud of that fact!

Posted on April 15, 2019, in WWII and tagged , , , , , , , , . Bookmark the permalink. 114 Comments.

  1. Ingenuity is definitely the mother of invention in this case mate.
    So much to learn from your posts gp.
    Cheers.

    Liked by 1 person

  2. Reblogged this on quirkywritingcorner and commented:
    Grenades are a fascinating weapon, like a mini-bomb. I should write a story that needs a grenade in the plot. I love the cartoons at the end!

    Liked by 1 person

  3. If I recall correctly the ones we used in the 1950s here, had to types of fuse, a long and short, the short was something like 4 seconds I believe the long was 7 or 8;

    I know I couldn’t get rid of mine quick enough during training. They were actually Mills bombs from the Great War, and nowhere near 1 lb in weight, I doubt I’d been able to throw a 1 lb’er very far

    The Germans made ceramic grenades back in the 17th century, what goes around comes around.

    Liked by 1 person

  4. I know of some horrible results with grenade implementation. Sad.

    Liked by 1 person

  5. A very interesting story

    Liked by 1 person

  6. I’ve never heard of ceramic grenades, G. It looks like they could be repurposed now as single rose flower pots. –Curt

    Liked by 1 person

  7. GP: I’m always bemused by depictions of grenades in war movies. You’d think those guys were throwing A Bombs with the huge explosions, smoke and fire. I chucked a couple of pineapples at Camp Wainwright. They just make a popping sound and the frags fly. Those frags can fly a long way though. I knew nothing about those Japanese grenades. Interesting.

    Liked by 1 person

  8. I’m really surprised that no one mentioned the ceramic insulators that were found on power poles all across this country for years. Even today, you can find those glass and ceramic insulators in antique shops, and there are active collector groups.

    No one mentioned the smudge pots that were used in orchards or along highways, either. I remember seeing them as a kid. The aerospace industry still is using porcelain insulators in some applications. I wonder if all of that resulted from the initial Japanese applications?

    Liked by 1 person

    • I really don’t know, but now that you’ve mentioned it, the subject would be interesting to look into. You do tend to think of things others miss (including me!! 🙂 ), Linda. Thank you for being you!!

      Like

  9. Ceramic grenades? Who’d have thunk it? There’s an elegance to the notion. Ingenious, indeed.

    “To whom it may concern.” *soft chuckle* Meh, to whomever the heck is around to sign for it. 😳 💥

    Liked by 1 person

  10. I’m wondering if perhaps they would feel safer just having it as a backup. But they would have been rather heavy to carry around with you. Practical me!

    Liked by 1 person

  11. Love both cartoons, especially the ‘non-discriminatory’ second one. 🙂

    Liked by 2 people

  12. I still think it would be a good idea for the arms industry (and the warmongers) to have to field test their products (in active-service) themselves. As users, not as coddled observers.

    Liked by 1 person

  13. Interesting. The things you learn about,

    Liked by 1 person

  14. This is new to me as I have never heard of a Ceramic Grenade before today! You know so much about the military.

    Are you on Pinterest or Facebook? I don’t like Facebook; I’m only on there to stay in touch with some important people in my life. xxxooo

    Liked by 1 person

  15. This is fascinating, GP; I could’ve never imagined that grenades, or any other weapons for that matter, would be made of such fragile materials.

    Liked by 1 person

  16. Scoring the surface of the ceramic before firing in the kiln might have produced the deadly fragmentation this design lacked. Just as well they didn’t think of that…

    Liked by 3 people

  17. Absolutely fascinating ! I’ve had trouble enough lighting road flares , and they didn’t explode after five seconds were I to delay or mishandle them.

    Liked by 3 people

  18. Very inventive! Years ago I read that the Japanese had invented a rust free ceramic car which was strong enough to crash without being significantly damaged. I would think that the pans for it are at the bottom of a deep, deep well at Toyota’s Fukushima factory.

    Liked by 2 people

  19. Excellent article, GP. Brand new information to me.

    Liked by 2 people

  20. I like the post, but not the weapon

    Liked by 2 people

  21. A ceramic grenade doesn’t seem like an inspired choice but I guess you work with what you have. Good humor today, GP!

    Liked by 2 people

    • I’m sure it wasn’t as effective, but “making-do” seemed to be the motto of that era – then again, what choice did they have?
      Happy you got a kick out of the humor!

      Like

  22. Yet another bit of info I wasn’t aware of. Ingenious of the Japanese to overcome the lack of metal and still build an effective weapon. I wonder about the failure rate. About halfway during my tour in Vietnam, they introduced us to the “baseball” grenade. We had been using the “egg” shaped ones (can’t remember the technical name). These were smooth bodied, not the “pineapple” surface. At first I was glad for the new round shape. However, there were a few produced that were “short fused.” This resulted in one Marine in my platoon who had a baseball grenade explode in his hand, blowing off his hand and most of his head when it exploded. After that, we scrambled to collect the egg shaped grenades. Sort of like the original M-16s they issued us. They jammed if you looked at them crooked. Newer models later on took care of the problems with the grenades and rifles, but those of us using the early ones considered them untrustworthy. Not a good thing for combat troops to have.
    Thanks for another informative post!

    Liked by 3 people

    • I remember those M-16s. They seemed to be more reliable if you didn’t quite load them to the max. But I hadn’t heard about the grenades – awful situation!

      Like

      • Yeah, we would rarely put more than 18 rounds in a magazine. Those open, 3-prong muzzle flash suppressors were like magnets to vines and other vegetation. We cleaned them as often as possible, but the slightest bid of sand or dirt and you had yourself a single-shot weapon, IF you could clear the jam in time. A few guys still carried the M-14s (a great weapon, IMO). They had to beg rounds from the M-60 teams. Oh how those M-14 guys were envied!

        Liked by 2 people

    • I’m not well versed on the M-16; however, the fault can be laid on the damn “chiefs”. They substituted the ammo intended for use which used a clean burning powder with far less residue. I did a quick search and thanks to the commenters got the “skinny” on the weapon’s jamming.

      The Original models of the M16 were trouble free. They fired a special round with a low residue charge so the mechanisms would not become fowled. But, when the Army bought large quantities of the weapons the ammunition that was supplied was filled with the same gunpowder that had been used for the M14. It gave the M16 more punch, but was dirty and fowled the weapon, which caused it to jam. Because the original weapons had been so trouble free the new mass-produced weapons that followed them were suppose to be maintenance free, so cleaning kits were not supplied with the rifle. Once cleaning kits were issued the problems cleared up, and the M16 proved to be a much better weapon in the hands of soldiers who were trained to keep their weapons clean.

      Source Was M16 prone to jammed during Vietnam War? | Yahoo Answers
      [Search domain answers.yahoo.com/question/index?qid=20130714215754AARQUiX] https://answers.yahoo.com/question/index?qid=20130714215754AARQUiX
      The jamming problem was something that happened early on when Robert McNamara ordered new M-16 not built to the specification of the original weapons. The cost cutting corners left the weapon prone to jamming unless it was cleaned on a regular basis.

      Liked by 1 person

  23. Crumbs! Now there is a cottage industry to revive for discontented voters!
    Sorry to say that my mother, ex ATS, died on March 24th….I will miss passing on your posts to her.

    Liked by 2 people

    • I am so sorry to hear that, Helen. Please accept my condolences. The world lost one of the good ones!!
      (If you wish her to be in the Farewell Salutes, please send me her basic info, like you are used to seeing in that column. I would be honored.)

      Liked by 1 person

  24. I’m considering investing in a kiln now….. 😀

    Liked by 2 people

  25. Another potentially deadly weapon that fortunately did not come into service. Great informative post, GP!

    Liked by 2 people

  26. Great post, I did not know about these. Once you pull the pin Mr. Grenade is no longer your friend.

    Liked by 2 people

  27. Very fascinating, and Germany do it again, producing several ceramic products for the future, here in the “Region of Dual-Use Companies”. Lol

    Liked by 2 people

  28. Haha…grenade…take a number!! Fire in the hole as the military say?!😃

    Liked by 2 people

  29. The ingenuity of munitions people is pretty remarkable.

    Liked by 2 people

  30. Interesting. Its great to discover these bits of information from you.

    Liked by 2 people

  31. A new knowledge again for me. Looking at that ceramic granite pile, they could recycle them into something beautiful for the home after the war.

    Liked by 2 people

  32. I wonder how many of us were harmed/injured by this weapon. This new info is greatly appreciated.

    Liked by 2 people

  33. Your posts contain such interesting, little know facts. Thanks.

    Liked by 2 people

  34. I never knew about these. Great job, GP on explaining the reasons/process and results. It’s scary, how little it takes to make weapons like this.

    Liked by 4 people

  35. The cartoons are very good! I recall some Japanese grenades that had a ‘striker’. The soldier would bang this against his helmet, or the ground, before throwing. I always considered that many grenades could be just as harmful to the thrower, as to the intended victims. 🙂
    Best wishes, Pete.

    Liked by 4 people

  36. Fascinating, informative post on something I never heard of, ceramic grenades.

    Liked by 2 people

  37. I like the grenade humour of; ‘Please take a number.’

    Liked by 3 people

  38. Great Piece GP! Please do more articles like this! Fascinating stuff!👍

    Liked by 2 people

  39. Thank you very much for your interest in this article, David.

    Like

  40. Much appreciated, Ian.

    Like

  1. Pingback: Featured Blogger Report: Type 4 Ceramic Grenades | Pacific Paratrooper #AceHistoryDesk reports | ' Ace Worldwide History '

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