Welcome to the Inert Ordnance Collectors.
  • Login:
Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Pom-1s

  1. #1
    Senior Member
    Join Date
    Jan 2011
    Location
    Dunstable.
    Posts
    102
    Thanks
    515
    Thanked 21 Times in 11 Posts

    Pom-1s

    T5048U02.jpg

    This WAAPM is obviously derived from the US BLU-42B, a fact which its designer, A.Popov, freely admits on his website-http://a-popov.livejournal.com/104592.html However, it is completly different internally, and also has an additional external safety, released by a pull wire when dispensed. Perhaps it does not use auto-rotation for arming, so it can be dispensed close to the ground for a greater density of coverage? Also it seems to use a hydraulic timer for arming, and a mysterious pyrotechnic lock connected with the external safety, in some mysterious fashion.

    Other differences are serrated ground engaging discs at the end of the trip-lines-perhaps the rather smaller ball anti-disturbance switch needed a stronger pull than the BLU- 42B? & separable spider-heads, so presumably to allow the shafts to remain in position, sealing against water ingress. If the battery is a reserve type(Probably) then perhaps the Pyrotechnic Lock is to provide enough force to release a strongly sprung striker, so crushing the electrolyte reservoir, as well as the hydraulic dashpot or sequence timer.

    Is there a fully sectioned view, as the Ordata image suggests, or perhaps Mr. A Popov might oblige! Someone must have a sectioned item, or a description of the action.

    Many thanks in advance,

    Martin.

  2. #2
    Ordnance Approved
    Join Date
    Dec 2010
    Location
    Illinois USA
    Posts
    947
    Thanks
    5
    Thanked 331 Times in 171 Posts
    Scan0003.jpgScan0004.jpgPOM 1
    IDENTIFICATION.
    a. (U) Type. The POM-1 and POM-1S are ground- or aircraft-dispensed, scatterable, electro- and hydromechanically armed, antidisturbance, antipersonnel (apers)landmines. The POM-1S also incorporates a self-destruct feature. Both mines deploy eight 6.00-meter (19.69-feet)-long tripwires. The POM-1 and POM-1S are identical in external appearance.

    DESCRIPTION.
    a. (U) Material. The mines bodies are steel.
    b. (U) Weight. The mines weigh 750 grams (1.65 pounds) each.
    3. (U) HAZARDOUS COMPONENTS. The main explosive charge weighs 100 grams (3.5 ounces) of an unknown composition. The pyrotechnic lock and fuze detonators are of an unknown weights and compositions.

    FUNCTIONING.
    a. (U) Arming. As the mines are ejected from the dispenser module, pyrotechnic locks ignite, safety pins are withdrawn (safety pins are part of module), and mechanical locks are released. When the pyrotechnic mixture has burned, the safety rod is pushed outward by a spring, ejecting the mechanical lock, clearing a path for the remote arming mechanism (MDV). The MDV housing is then moved by a compressed spring, slowly overcoming the resistance of the liquid silicon (not shown) surrounding it. The arming time varies from 1 to 10 minutes depending on ambient temperature.
    After half of the arming time has elapsed, the MDV housing has moved far enough to release an electrical contact lock, which enables part of the electrical circuit and begins to charge the capacitor. When the arming time expires, the MDV housing closes an electrical contact, releasing power to the pyrotechnic pusher allowing a shutter to turn, cutting the shutter pin. At this point, the tiltball switch is armed, but the tiltball is prevented from making electrical contact. The lockballs holding the X-shaped covers drop into cavities in the shutter, allowing the X-shaped covers to be ejected as springs under each tripwire drum expel the drums outward. The tripwires unwrap as the drums travel through the air.
    b. (U) Firing. At this point the mine capacitor is fully charged and the tripwires are deployed. Any movement of the mine or pulling of the tripwires tilts the mine body allowing a tiltball to touch electrical contacts.
    The tiltball, making electrical contact, closes a circuit allowing the capacitor to discharge to the detonator, initiating the explosive train. The POM-1S mine will self-destruct following a delay of 1 to 40 hours if it has not been disturbed. Operational life of a deployed POM-1 mine is from 5 to 15 days. Lethal radius of the mine is 4.00 meters (13.12 feet).
    any live or dug ordnance shown in my posts was dealt with by EOD personell

  3. The Following User Says Thank You to weberoed For This Useful Post:

    Sprockets (30th June 2013)

  4. #3
    Senior Member
    Join Date
    Jan 2011
    Location
    Dunstable.
    Posts
    102
    Thanks
    515
    Thanked 21 Times in 11 Posts
    Thanks, Weberoed, for the information about the functioning, which gave previously unknown details. It states that safeties include withdrawal of a safety pin, pyrotechnic lock and removal of a mechanical lock.(I suppose this means that the cross-shaped retainers for the spring-loaded line ejectors are obstructed when in the dispenser by packing?)

    As for the Pyrotechnic Lock, I have only just realised that a fuse-train in the dispenser flashed through a hole in the outer part of the lock (Passing around the safety pin, which is still not released at this point), so igniting a slow-burning compound, which eventually allows a spring to withdraw the lock on the hydraulic dashpot (MDV). If it burnt slowly enough, it could only release the dashpot after impact on the ground. Then the initial closure of contacts, though the dashpot releasing the ball-lock shown, would charge the capacitor, and possibly remove a lock on the ring. Further movement of the MDV would close contacts to fire the pusher(Dimple unit), rotating the ring to shear a pin and freeing the cross-retainer ball-locks. The lines are then ejected.

    The plunger which engages the contacts connected to the capacitor probably simultaneously disengages from a hole in the ring.Thus firing of the pusher by heat or stray EMF would fail to move the ring, which would remain bolted. Similarly, should the dispenser be subjected to heat, the pyrotechnic lock could not activate the unit, as the safety wire would be in position. I am not sure how heat could be prevented from firing the ejection cap, which would then operate the ejector charge, and the submunitions then be armed?

    It is then stated that the tilt-ball switch is armed, but the tilt-ball cannot make contact. Is this correct, as there doesn't seem to be a lock for the switch? Could the MDV unit close an additional switch? Does anyone have a picture showing the dashpot(MDV) construction, as this is the heart of the device, and also if the battery is of a reserve type? Further, was the MDV unit additionally used to neutralise the unit after a longer period?

    It is most unusual that the unit was not centrifugally armed, especially as it has already vanes to spin it to widen distribution. Could a pyrotechnic lock be used to ensure that it would still function if the helicopter dropped it close to the ground. Could 'copter downwash lead to premature arming if spin was used?
    . However, I don't see how, as mentioned above, the weapon could ever be made fully safe against a ground fire involving the launching craft!

    Another unusual feature is that the plungers retaining the cross-plates only move a short distance, before the cross-plates disconnect. Probably this is to ensure that the mine stays water-tight, as the plungers continue to block the holes.

    As this submunition was designed by the nimble mind of A. Popov, perhaps this query could be brought to the attention of his website, perhaps by a Russian speaking member of the forum? Incidentally, he obviously has a high regard for the excellent Russian Ordnance site, Sapera.ru, as he mentions it in his website. If anyone has yet to visit it, don't delay, because you don't know what you are missing! Even if not everything has been translated into English, the diagrams are fantastic, and often self-explanatory.

    Thanks in advance for any further information on this submunition.

    Martin.

  5. #4
    Senior Member
    Join Date
    Jan 2011
    Location
    Dunstable.
    Posts
    102
    Thanks
    515
    Thanked 21 Times in 11 Posts
    Following close inspection of Ivashkin's excellent site, www.saper.etel.ru/mines-2/pom-1.html, there is a totally different explanation of what happens on ejection form the dispenser. After the ignited pyrotechnic lock burns out, a spring operates to retract a locking pin from a central spindle, so allowing centrifugal force, developed as a result of auto-rotation, to move the silicone fluid-damped(MDV) central spindle against the spring, and close contacts(Not shown) to charge the capacitor and supply current to the anti-dist. sw. Somehow this also releases the small ball lock securing the shutter ring, allowing turning of the shutter plate, releasing the crosses (2)(Balls drop into holes in plate) and allowing the spring loaded anchors, assisted by the centrifugal force, to extend while the sub is still spinning in the air. Only after the munition lands and stops spinning, does the spring on the MDV unit re-exert itself and return the heavily damped central spindle back to its initial position (Where it was previously locked by the pin extending from the pyrotechnic lock) and beyond, allowing the electrical contact lock to shut and connect the current-interruption sensor electronic circuit output to the detonator. As it is fitted with a normal battery, eventually this will become discharged, unless the bomblet is fitted with an electonic timer to sterilise it. This is completly different from the US BLU42, which ejects the trip-lines when stationary on the ground.
    This difference in operation could be explained because the BLU 42 was meant for a jungle environment, so trip-lines already deployed would become entangled in the jungle canopy. Instead, an impact sensor deploys the trip-lines many minutes after operation, so that even if initial impact is made against a branch, there is still plenty of time for the unit to gradually fall to the ground, passing through dense vegetation on the way down. However, ground deployment has several disadvantages-A)-Possibly only half the lines will avoid impacting the ground adjacent to the device B)-The anchors will not bury into the ground, so that it is more likely to slide along the ground when the enemy comes into contact with a line. This perhaps explains why the US type has a very large diameter & sensitive anti-disturbance switch, compared to the tiny Russian switch. The Russian anchors also have serrated discs to assist ground burial. The centrifugal force on the trip lines will ensure full deployment, even if a strong wind is blowing. Since the retaining stars for the anchors have to be ejected during spinning, this may explain why the end portions become disconnected during ejection, as wind force may tend to cause the spindles to jam, should they be in one piece. Thus the Russian device, in the original non-sterilising form, had only need of one electronic board to sense current interruption in the anti-disturbance switch. Ivashkin remarks that the battery was not at its best in cold weather, which is why probably a capacitor was used. All in all, a much simpler internal structure than the BLU42, and deploying more of its trip-lines in a non-jungle situation.

    The main worry about this scenario is whether it would be such a good idea to have the trip lines whirling in the air, and tangling with adjoining bomblets, and becoming tangled when the munition hit the ground and stopped rotating quickly. If the explanation posted by eodtec was modified slightly to bring it more in line with Ivashkin, but deploying on the ground, then, after the pyrotechnic lock had released, centrifugal force would prevent the MDV unit moving. Only after spinning stopped on ground impact, would the MDV plunger be free to slowly move. First it would release the electrical contact lock, allowing the capacitor to commence to charge,as well as supply current to the anti-disturbance switch and also release a ball lock, just visible, to free the arming shutter. The ball-locks securing the X-retainers for the anchors would release & allow the anchors to eject as previously. Further travel of the MDV would trip another switch ( not seen) to connect the detonator to the output of the no-current flow electronic sensor for the anti-disturbance switch, which would allow the capacitor to discharge on sensing no current. However, there is considerable divergence between Weberoed and Ivashkins scenarios, to whom, as well as pzgr40, I am most grateful. Any suggestion or criticisms of my explanations, and as to why there appears to be this divergence in explanation ? Ivashkin notes quantities of the POM-1s were not large, and it remained unknown to most troops. Perhaps this explains the varying descriptions of its operation, as perhaps none were ever physically examined by EOD .

    Any experts care to comment?

    Martin.

  6. #5
    Junior Member
    Join Date
    Jun 2008
    Location
    Ukraine
    Posts
    8
    Thanks
    3
    Thanked 3 Times in 2 Posts
    Hi Martin,
    I am not a "big expert" in ussr after WWII munitions, but I have some info, so info on www.saper.etel.ru not complited - on pictures you may see detail #14 its moved from liquid caoutchouc and after some time relies balls #10 and it relisted the X-retainers.
    POM 1S 00.gifPOM 1S 01.gif


    And release & allow the anchors takes place already on the ground.
    After a while I am ready make a accurate translation of the POM-1 S instructions.


    WBR,
    Poroch



  7. #6
    Ordnance Approved
    Join Date
    Dec 2010
    Location
    Illinois USA
    Posts
    947
    Thanks
    5
    Thanked 331 Times in 171 Posts
    Poroch
    would really like to see the translation of the POM-1S. thank you in advance

    Mike
    any live or dug ordnance shown in my posts was dealt with by EOD personell

  8. #7
    Senior Member
    Join Date
    Jun 2007
    Location
    Germany
    Posts
    2,627
    Thanks
    31
    Thanked 612 Times in 401 Posts
    POM-1_0000.jpgPOM-1_0003.jpgPOM-1_0002.jpgPOM-1_0001.jpg
    Attached Images Attached Images

  9. The Following 3 Users Say Thank You to EOD For This Useful Post:

    frogman (10th April 2016), Joerg (13th February 2014), Sprockets (24th January 2014)

  10. #8
    Junior Member
    Join Date
    Jul 2011
    Location
    united kingdom
    Posts
    7
    Thanks
    1
    Thanked 0 Times in 0 Posts
    Hi, very nice set of pictures and text. EOD, may I ask what was the source for the last post? I am trying to get my head around the electronics mechanism of the tilt switch on page 23. Do you understand any of it? electronic symbols seem strange. What are зпн; зпт; and зд ? I'd really appreciate if you'd help. For some reasons it is very satisfying when I understand a fuze mechanism. Thanks
    Last edited by frogman; 10th April 2016 at 12:10 AM.

  11. #9
    Senior Member
    Join Date
    May 2013
    Location
    Mazet-Saint-Voy, Auvergne
    Posts
    831
    Thanks
    604
    Thanked 940 Times in 403 Posts
    Hi


    Found just now on internet, photos of the cluster pictured in the last image of EOD's post.

    RU_CGO_KPOM1S.jpgRU_CGO_KPOM1Sbis.jpg

    Regards,

    S.

  12. The Following User Says Thank You to sgdbdr For This Useful Post:

    Sprockets (27th January 2019)

  13. #10
    Junior Member
    Join Date
    Jul 2011
    Location
    united kingdom
    Posts
    7
    Thanks
    1
    Thanked 0 Times in 0 Posts
    This is a diagram for tilt ball switch of POM-1S. A is plastic container, B is a metallic ring with metallic tilt ball inside and C are two metallic rings. Regardless of what position the mine lands, B is going to make a contact with C. This 'make and break' contact action doesn't matter during the arming delay period. But, after the expiration of arming delay, any movement of mine causes the contact between B and C to break momentarilly and the sensing electronics detect the current interruption and send a signal to a transistor or SCR which open the patch for discharging of firing capacitor to detonator. I'd really like to see sensing electronic diagram for POM-1S or BLU-42B, but there is no publication that I can find. One curious collector could easily trace the components and produce a diagram though, if he is inclined.


    Tilt sensor.jpg
    Last edited by frogman; 27th March 2017 at 01:01 AM.

 

 
Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Back to top