BLU-42 A/B or BLU-54 cluster mine, USA.

[pzgr40]

Cutaway model of a BLU-42 A/B or BLU-54 cluster mine. This type of mine is also named minelet or WAAPM (Wide Area Anti Personel Mine). 540 of these mines are packed in a CBU-34 (Cluster Bomb Unit), either 540 pcs in the SUU-38A dispenser (remains underwing) which can throw out 10 canisters of 54 minelets.
The mine exists of two machined cast steel halves, connected by means of a rolled steel band. Eight holes have been drilled in the minelet body to house the bushings that contain the trip wire reels.
In the body, a (non type designated) fuze is placed that exits of a safe and arming mechanism, en electronic movement sensor (fuze), two electronic timers, a spider release mechanism and an electronic self destruct mechanism. The explosive charge exists of 71 grams comp. B.

List of fuze parts:
1- Upper fuze body half
2- Lower fuze body half
3- Rotor housing
4- Cover and pivot rotor(housing)
5- Centrifugal weights (4x)
6- Centrifugal weights press springs (4x)
7- Safety ring with safety fork
8- Safety ring spring
9- Balls (2x)
10- Electric connector pin
11- Electric connector pin spring
12- Rotor
13- Slider contact
14- Soft rubber pressure piece for under slider contacts
15- Axial lock up clip rotor
16- Retaining clip gas driven piston
17- Gas driven piston
18- Electronic firing cap
19- Detonator
20- Axial retainig pin (2x)
21- Housing spider release mechanism (2x)
22- Spring-ring (2x)
23- Radial release pins (2x)
24- Spider release pin (2x)
25- Rubber gasket
26- Spider release mechanism housing cover (2x)
27- Spider
28- Electronics ring
29- Battery with switch connector
30- Isolator disc
31- Gasket ring
32- Lower ring of anti disturbance circuit
33- Housing of anti disturbance circuit
34- Upper ring of anti disturbance circuit
35- Contact balls of anti disturbance circuit
36- Tripwire with spool and spring

Functioning of the mine:
As each mine is released from the cluster bomb or dispenser canister, the airstream catches the flutes, spinning the mine with 2700 +/- 300 rpm. to provide the centrifugal force required to start the arming sequence. Four centrifugal weights (5) are thrown outward -overriding the springs (6) that try to keep them inward-, enabeling the safety ring (7) with the attached safety fork to move down under the influence of the spring (8) above it. This releases two balls (9) that fall outward, enabeling the electric connector pin (10) to move upward under influence of it’s spring (11), closing the electric circuit under the battery (29). Also, the safety fork –connected to the safety ring (7)- moves down, releasing the rotor (12). The Rotor has three goals: It switches the electric contacts by means of a slider contact (13), It releases the spiders (27) that releases the eight tripwires (36) and it moves away a sliding safety between the electric firing cap (18) and the detonator (19).
As soon as the minelet hits the ground an electric switch activates a timer that provides a primary stabilization delay of 5 to 10 minutes prior to trip line deployment. At expiration of the primary stabilization delay the gas driven piston (17) is activated and pushes the rotor (12) in it’s working position. Two axial pins (20) that rest on the rotor will now fall inward together with the blade springs (22) on top of these pins (20). This will allow two radially placed pins (23) in the spider release housing (21) to move outward and free the spider release pins (24). Now the spider (27) is released and jumps away, allowing eight trip lines (36) to be deployed out to 7.62 meters (25.0 feet) from the mine. A self-destruct timer and antidisturbance firing circuit (32,33,34) are also activated at this time. As the antidisturbance firing circuit is activated, a secondary stabilization delay of 6 seconds prevents premature detonation during trip wire deployment. At the end of the secondary stabilization delay, the mine is fully armed.
In the ideal situation, with all trip wires extended to full length, an area of 10,8x10,8 mtrs is covered, either 117 square meters.

The mine has an electronic self destruct mechanism:
BLU-42/B - 156 hours; 6,5 days
BLU-42 A/B- 180 hours; 7,5days
BLU-54/B- 1200 hours; 50 days.

This mine was used extensively in the Vietnam War and has since been exploited and copied by the former Soviet Union under the designation POM-1S.
The diameter of the BLU-42 A/B or BLU-54 is 60 mm.

A special thanks to US-Subs who helped me out with info about the functioning of the fuze.


Regards, DJH

 

[pzgr40]

BLU-42 A/B or BLU-54 cluster mine, USA , Pt2

More drawings

 

[SG500]

What an amazing cutaway psgr40, thanks for posting the great photos and write up, good work!!
Dave.

 

[pzgr40]

Thanks SG500. when I was able to get a -parts complete- BLU-42 I found it interesting enough to make a full study with acad drawings of the functioning of the fuze and change it into a nice cutaway model.

regards, DJH

 

[HAZORD]

Very thorough explanation and very nice sectioning DJ! You must have clones that work on this stuff 24/7. Amazing!

 

[pzgr40]

A clone of me? That would mean two ladykillers.:tinysmile_tongue_t:

 

[HAZORD]

Hint: They will always die when you section them!

 

[pzgr40]

Ahhhh, that's why they become so silent. Thanks for the tip:angel:
Rgards DJH

 

[blu97]

Again a great cutaway, thanks for showing.

 

[Madbomber31]

Clone DJ!!!! That will be a big problem here for the Army they will have no stuff left he will cut up everything :xd:

Nice work again DJ

 

[pzgr40]

Thanks folks! The biggest job in making this cutaway model was making the ACAD drawing of the fuze and translating the posting in three languages ; Dutch, German and English. There is some more interesting submunition and minelet stuff on the way (I still have to finish it).


@ madbomber
Taking into account however the latest financial cuts and the investment stop the Dutch Army is suffering from now -according to the papers-, soon there'll be nothing but thin air left to be cut :tinysmile_angry2_t:.

 

[butterfly]

pzgr40 - Amazing!! Your sections never fail to impress. Your write ups are also fantastic.

What I would like to know is if you have an all-time favourite from all the different sections you have done? If not one then maybe your top few??

regards
Kev

 

[pzgr40]

It's some different series. For instance the DPICM shells, The 8,8cm Flak 18 shells (1 to 21, just received No. 22 and 23), the collection of 35x228 shells and some other stuff. I am also preparing a posting about a AA-1 Alkali cutaway, however I have to find someone who can translate russian to English for me.

 

[butterfly]

It's some different series. For instance the DPICM shells, The 8,8cm Flak 18 shells (1 to 21, just received No. 22 and 23), the collection of 35x228 shells and some other stuff. I am also preparing a posting about a AA-1 Alkali cutaway, however I have to find someone who can translate russian to English for me.

To see a collection of cut-aways together like that is amazing!! What a fantastic photo!! Well done pzgr40 - thanks for showing.
regards
Kev

 

[commachio]

Does ANYONE know where I can get an inert BLU-42? I have been trying to get one of these for a while now but don't seem to be getting anywhere.

many thanks and regards

 

[US-Subs]

There are very few 42/54s around. I know of about 10, all in collections and I know of no extras.

 

[Dragontooth]

OK, gentlemen, this is my very first post here...so I hope it is not seen as unnerving or annoying.

As I mentioned in the about myself section, I am deeply interested in the production history of munitions, i.e. which firms or state-owned contractor operated (GOCO) or GOGO plants produced them.

So, I would like to know as much as the experts here are willing to tell me about the development and production of the BLU-42 and 54 munitions during the Vietnam war.

I will take a wild guess: maybe Honeywell for fuzes and Aerojet for the explosive?
If you do reply, please refer to which part was manufactured by whom, e.g.
fuze: Honeywell
munitions body: Hayes International
explosive: Aerojet

etc.
The above is just and example, I may be WAY off...

Thank you to all who participate.
The pictures and info are superb PzGr40.
dave

 

[carek]

Great job with pics and description of function

 

[weberoed]

So how would you compare this one to the Soviet POM-1 and 1S? By all descriptions the Soviet did a one for one copy if the BLU 42.

 

[EOD]

The Russian POM-1 is somewhat different.