Monday 16 February 2015

Valentine MkIX Trials

The Red Army has been a fan of the Valentine tank for many years, so when a new modification with a 57 mm gun that solved both the problem of an ineffective AP shell, one was naturally ordered for trials.

Valentine MkIX tank at Kubinka, March 1943

Valentine MkIX observation range (driver).

Valentine MkIX observation range (turret).

"Firing in place and on the move

Gunnery trials were performed at ranges of 500 and 1000 yards (457 and 914 meters) at targets 4x6 meters in size. Each group had 10 shots. There was no time limit on firing. Aiming was done using the telescopic sight. The weather was clear, visibility was 2000-2500 meters.

Results are given in table #4.



Range (yards) # of shots # of hits Mean vertical deviation, cm Mean horizontal deviation, cm
In place 500 10 10 11 8
In place 1000 10 10 18 16
Moving at 10 kph 400-500 10 10 95 75

Comparing the data in table #4, one can see that:
  1. Mean vertical deviation is higher than mean horizontal deviation in all cases. This is explained by a wobble in the elevation mechanism and a turning of the flywheel when the firing lever placed on the flywheel is pulled.
  2. Mean deviation when firing from the move is 11 times greater than when shooting from a standstill from the same distance. This happens due to the stiffness of the suspension and the insufficient traction of the tracks on the ground, which leads to the tank slipping and the turret wobbling, which makes it difficult to aim the gun.
Maximum rate of fire in place and on the move

The maximum aimed rate of fire was measured at a range of 700-1000 yards (640-914 meters). Aiming was performed using the telescopic sight using the mechanical aiming mechanisms. Each group consisted of 5 shots. The weather was clear, visibility was 2000-2500 meters.
Results of trials and hits on target are given in table #5.

Condition # shots


Result Time


RPM % hit
Hit Close miss Overshot Undershot Deviation in direction
In place. Range= 1000 yards 5 3 2 - - - 30 sec 10 60%
Moving at 9-10 kph, at 0 degrees, at one target 5 2 2 - 1 - 1 min. 51 sec. 2.7 40%
Ditto, at two targets 5 1 1 1 2 - 1 min. 47 sec. 2.8 20%
Ditto, at three targets 5 - - 2 3 - 2 min. 4 sec. 2.5 0%
Average













2.7 20%
Moving at 15 kph, at 0 degrees, at one target 5 - - 3 2 - 2 min. 24 sec. 2.0 0%

Summary
  1. The English Valentine IX tank differs little from the Valentine III tank. The main difference is the use of a 6-pdr gun in the Valentine IX, a lack of coaxial machinegun, and thinner side armour.
  2. The speed and maneuverability of the two tanks are nearly identical, with the exception of range, which increased in the Valentine IX by 90% due to external gas tanks.
  3. The 57 mm gun on the Valentine IX has an unreliable recoil brake.
  4. Unsatisfactory results when firing from the move, 20% hits, are achieved due to significant wobble in the aiming mechanisms.
  5. A lack of HE grenade for the 57 mm gun limits the usefulness of the gun.
  6. A lack of coaxial machinegun limits the usefulness of the tank when fighting enemy infantry.
Conclusions
  1. Valentine IX and Valentine III tanks are equivalent technically.
  2. The armament of the tank makes it only useful against enemy tanks.
  3. The lack of an HE grenade and a coaxial machinegun makes the tank unable to fight enemy infantry and fortifications.
  4. The reliability of the 57 mm gun needs to be tested on a series of samples."
CAMD RF 38-11355-1540

9 comments:

  1. If british werent able to equip it with HE ammo, should soviets use for that gun ammo from the ZIS 2?

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  2. Any reason the Soviets were measuring the targeting and dispersion distance in yards? Did Soviets do their own test or translated British data?
    -m

    ReplyDelete
    Replies
    1. The dispersion distance seems to be in cm, as for the targeting ranges, presumably that's because yards are what's on the scope's reticle.

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    2. Odds are they were using British ballistics tables, which would be in yards.

      Delete
  3. There may be something wrong with that data. If the target is really 4x6 meters (13.1 x 19 feet) then with those dispersion numbers there should be a 99% chance to-hit from 1000 yds. (A 60% chance to-hit that size target would assume a mean deviation ranging error of 17%.)
    -m

    ReplyDelete
    Replies
    1. The simplest explanation I can think of is that the stationary test involved two or three targets (the number of targets is not explicitly written only in that row). The 1st shot close missed target 1 due to an operator error, the 2nd shot (corrected) hit it, the 3rd shot close-missed target 2, the 4th shot hit it and the 5th shot hit target 3.

      Delete
    2. In this:
      http://tankarchives.blogspot.com/2014/04/lend-lease-impressions-aec-mkii.html
      The gun in a different vehicle with similar dispersion hits the target at 700m 100% of the time.

      Delete
    3. And it hits 100% of the time at 1000m here. The trick is in the "3)", where the chance decreases to 85% when short-stop firing. In USSR, you get 6-8 seconds to fire your shot after short-stopping, which is a bit more than the 6 seconds per shot in this text.

      In short, for fully prepared shots, 100% hits can be expected. For hastily prepared shots, the chance of actually getting a hit is about 60-80%.

      Delete
  4. There was a HE shell available for the 6 pdr from approximately Jan-Feb 1943.

    Is there a date for when this trial was conducted? Either the British hadn't built up their own stocks sufficiently when this tank was sent, or if it was a later trial they just neglected to send any HE with this tank.

    ReplyDelete