River Plate: were the British outgunned?

[Karl Heidenreich]

Now that the Graf Spee is again the talk of the town I think that it´s good to talk about her sad history (aparently all tales of German ships are sad).
If you search at the internet or in history books all of them agree that Graf Spee clearly outgunned the British cruisers that opposed her. The Exeter had 8" mountings and Achilles and Ajax had 6". The Spee´s 11" were superior, on paper. And that´s the history which, at the end, sells: evil superior nazi foe is defeated by three inferior cruisers.
But there is a point with the fact that the British were three and the German only one: three cruisers are a very serious, if not fatal, foe for a "pocket battleship" (in real terms a "commerce raider" no more heavy than most cruisers, no Battleship at all).
The British could (and they did) disperse the German limited fire while they had a lot more main turrets and mountings fixed on their enemy. The Exeter succesfully draw the main German fire as the other two cruisers approached were the superior range of the Spee was no longer an advantage, then engaged her. And engage an already damaged vessel. I´m not talking of fair play or not, because in war there is no such thing: winning or losing are the only concerns (living or dying for those who fight), but I´m talking about the aftermath: the talking about Spee´s defeat against "inferior" adversaries.
It´s obvious that not such initial German superiority was real. As a matter of fact the Spee was outnumbered and her inteligence gathering was lower than that of Comodore Harwood (the British cruiser´s CiC), because he knew pretty well the odds while the Langsdorff didn´t (at first he believed he was engaging an escorted convoy, not a Battle Squadron).
In this order of things the Battle of River Plate was an astounding fighting piece of a single German Raider against a British Cruiser Battle Squadron (one with reinforcement en route, by the way), in which her bigger artillery was compensated by enemy numerical superiority and deepest inteligence. At the end the superiority lies on the British side, not German.

[RF]

The key to looking at an issue like this is not so much the firepower available but really as to how effectively it is applied.

From the German angle, compare the River Plate action with that of Denmark Strait. In both cases the side initially outgunned emerged the winner; at River Plate the superior firepower was not accurate or concentrated enough to achieve a quick victory (ie. failure to quickly sink Exeter before the light cruisers were in effective range). At Denmark Strait we had a decisive strike in minutes, with the sinking of Hood.

In fact this factor is often the key to battles which ''do not go the right way.''

[lwd]

I'm (much to my surprise) agreeing with Karl this time. I guess in part it depends on how you define "out gunned" however, the Spee had a lot more guns firing at her than she had firing back. While the Spee's 11" guns were going to hurt anything they hit and in theory Spee could take 6" hits. Given her situation Spee was definitly the under dog. The battle would have been touted as a massive German victory if it had occured say 50 nm from Kiel. Spee was also shooting very well and getting hits (the two are not necessarily the same). The situation was also such that her range superiority was largly non existant. In short this was one that the British were almost guaranteed to win as long as they were willing to pay the price. Harwood was and they did.

[Bgile]

Anyone know why some who have reported the battle state that AGS had to fire in local control after her main FC position was put out of action? She had a secondary position.

[tommy303]

I don't believe the fore top artillery post was ever out of action, although the range finder was damaged; the directors were undamaged and continued throughout the battle to fulfill their function. One of the 15cm battery directors in the conning tower was damaged by a splinter that jammed part of the mechanism, but the problem was not found until the AGS reached Montevideo; this probably explains the lack luster performance of the 15cm during most of the action. There was however, a problem initially with A Turret, which due to a mechanical fault did not align properly with the fire control system. This entailed local control until the fault was rectified after several salvos.

There were times during the action when the main battery divided its fire against several targets and when it might have been useful to shift command of one division to the after FC station. However, the I.AO did not relinquish oversight during these instances, which meant shifting to local control for the turret not controlled by a director in the fore top.

[RF]

, the Spee had a lot more guns firing at her than she had firing back. While the Spee's 11" guns were going to hurt anything they hit and in theory Spee could take 6" hits. Given her situation Spee was definitly the under dog.

I'm wondering whether these two sentences are a contradiction. The way I see it the AGS should have won but was undone by the tactics of Langsdorf in closing the British and not concentrating on Exeter, in other words the AGS lost the initiative.

[lwd]

Should one heavy cruiser be able to beat one heavy and two lights? Did GS have enough ammo to defeat the British cruisers in a long range battle? By the time it was recognized what they were facing GS really didn't have any good choices left. As for concentrating on Exeter she did. But if GS wanted to make it home she had to disable all three British cruisers (2 might have been enough). Once Exeter was clearly out of the fight and the persuit shifting fire to the other British cruisers was the only thing that made sense. How badly hurt she was probably was not clear until well after the battle.

[RF]

Heavy cruiser - well if we are talking Hipper classe then yes.

But AGS had 11 inch guns, whereas the Washington Naval Treaties had limited heavy cruisers to 8 inch gun calibre. Here we are talking about a ship with punching power somewhat in excess of the standard 8 inch gun merchants and I think ''pocket battleship'' is the most appropriate description. And with a weight of shell substantially in excess of cruiser size AGS should have won - on paper.

[lwd]

She may have had 11" guns but she only had 6 of them and cruiser level armor. I disagree that she should win on paper. Indeed I'd give her only a 50:50 chance vs one of the large US light cruisers.

Weight of fire is a somewhat questionable MOE but lets look at it any way. GS guns fire a 300 kg shell at 2.5 rounds per minute according to:
http://www.navweaps.com/Weapons/WNGER_11-52_skc28.htm
So she's putting out 4,500 KG/minute from her main battery.
Exeter shells weighed in at 116kg and are rated at 3-6 rounds per minute.
So she's putting out 2,088 to 4,176 KG/minute from her main battery. From just under half to almost equal.
Now let's look at Ajax and Achilles they have a 50.8 KG shell and are rated at 6-8 rounds per minute.
Each of them can thus put out from 2,438 KG/minute to 3,251 kg/minute.

So the British force was capable of putting out from almost 7,000 KG/minute up to over 10,000 kg/minute. More than double GS output. Now GS hits will be more telling but the British should be hitting much more frequently and if the mission is to end GS cruise and perferable insure that she doesn't return home they don't have to sink her just inflict significant damage which they did.

[Bgile]

I think 2.5 rpm for the skc34 is a misprint. It's listed as 3.5 for the skc38, which seems more reasonable to me as a maximum rate of fire for that gun and it agrees with what I've seen elsewhere.

[lwd]

Ok, but that still leave the GS at 6,300 kg/minute which is less than the British force.

[tommy303]

I think 2.5 rpm for the skc34 is a misprint. It's listed as 3.5 for the skc38, which seems more reasonable to me as a maximum rate of fire for that gun and it agrees with what I've seen elsewhere.

I believe the 2.5rpm is correct for the SKC28 and the 3.5 correct for the SKC34. In the pocket battleships space restrictions limited the number of ring cars (which carried shells around the base of the rotating trunk) to two, each carrying one shell. When these were loaded into the hoists for the right and left guns, one car was rotated around to pick up a shell for the centre gun and take it to the center hoist. In the later Scharnhorsts, the arrangement was modified so that all three hoists could receive a shell at the same time. I do not remember exactly how this was done, but I seem to vaguely recall there being a third ring car on an inner track. This received a shell from the conveyors by means of an overhead rail (if I remember correctly). The modified arrangement accounted for the increased potential rate of fire.

[Tiornu]

Actually, 0 rpm is the accurate figure for the forward mount during the extended period when it was malfunctioning.

[dunmunro]

Weight of broadside in lb (no evil nazi Kgs here )

GS 6 x 660 = 3960 + 4 x 100 = 400 for a total of 4360lb

Exexter 6 x 256 = 1536lb

Ajax 8 x 112 = 896

Achilles = 896

Total GS = 4360lb
Total RN = 3330lb

In theory the RN force could use its higher RoF to match the GS, but the mundane issues such as ToF and 1930s FC limited the practicable RoF:

Note: Time of flight for CPBC Shell with MV = 2,700 fps (823 mps)
5,000 yards (4,570 m): 6.6 seconds
10,000 yards (9,140 m): 15.9 seconds
15,000 yards (13,720 m): 29.4 seconds
20,000 yards (18,290 m): 47.2 seconds
24,500 yards (22,400 m): 71.4 seconds

so even at 15K yds, the RN 6" gun was limited to about 4 salvos minute or 2 broadsides/min if the FoS is to be observed and FC corrections made. Even at 10k Yds the average RoF will not exceed 4 RPM. The 8" gun shows a similar story:
Note: Time of flight for SAPC Shell with MV = 2,725 fps (830.5 mps)
5,000 yards (4,570 m): 6.2 seconds
10,000 yards (9,140 m): 14.1 seconds
15,000 yards (13,720 m): 24.7 seconds
20,000 yards (18,290 m): 38.4 seconds
25,000 yards (22,860 m): 55.9 seconds
29,000 yards (26,520 m): 78.6 seconds

This is the ToF for the USN 12"/50 as I couldn't find data for the KM 11"
Note: Time of flight for AP Shell with MV = 2,900 fps (884 mps)
4,000 yards (3,660 m): 4.4 seconds
20,000 yards (18,290 m): 30.1 seconds
22,000 yards (20,120 m): 34.3 seconds
24,000 yards (21,950 m): 38.7 seconds

at you can see that at 20k yds, the shorter ToF of the 12" shell means that it actually has a higher RoF if the FoS is used to make gunnery corrections.

(data from Navweapons)

I should also add that GS could use base or nose fused 11" HE rounds that were far more destructive than the SAP rounds used by the RN, and the weight of broadside or even total weight based upon RoF doesn't take this into account. The base fused HE rounds could probably still penetrate any armour carried on the RN cruisers.

[Bgile]

I believe the 2.5rpm is correct for the SKC28 and the 3.5 correct for the SKC34. In the pocket battleships space restrictions limited the number of ring cars (which carried shells around the base of the rotating trunk) to two, each carrying one shell. When these were loaded into the hoists for the right and left guns, one car was rotated around to pick up a shell for the centre gun and take it to the center hoist. In the later Scharnhorsts, the arrangement was modified so that all three hoists could receive a shell at the same time. I do not remember exactly how this was done, but I seem to vaguely recall there being a third ring car on an inner track. This received a shell from the conveyors by means of an overhead rail (if I remember correctly). The modified arrangement accounted for the increased potential rate of fire.

Thank you! I now remember reading something about that also and I had forgotten.