Speeds at River Plate

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Dave Saxton
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Speeds at River Plate

Post by Dave Saxton » Wed Sep 24, 2014 1:59 am

Does anybody know how fast each combatant was moving at the Battle of River Plate?
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Re: Speeds at River Plate

Post by alecsandros » Wed Sep 24, 2014 5:38 am

Dave Saxton wrote:Does anybody know how fast each combatant was moving at the Battle of River Plate?
According to British accounts,
Exeter/Ajax/Achilles were doing 14kts at 6:14. AGS was doing 24kts and moving towards the cruisers at 6:14. Again, according to British accounts, AGS averaged 22kts during the battle phase (6:18 - 7:40)

All British cruisers started to accelerate towards maximum speed at 6:14. By 6:36, Achilles reports 31kts and Ajax was keeping steady with her, so it must have had 31kts also. It does seem a bit quick to come from 14 to 31kts in 22 minutes... Some info on power curves would be most welcomed.

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Re: Speeds at River Plate

Post by dunmunro » Wed Sep 24, 2014 9:21 am


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Re: Speeds at River Plate

Post by alecsandros » Fri Sep 26, 2014 8:03 am

Thanks, Duncan. So they could accelerate in that time.

According to S.D. Waters' battle reconstruction, HMS Exeter was doing "more than 25kts" at 6:20 and continued to accelerate (towards 31kts).

"The British cruisers were rapidly working up to full power and were steaming at more than 25 knots when the Exeter opened fire at 6.20 a.m., with her four forward guns"

http://nzetc.victoria.ac.nz/tm/scholarl ... vy-c4.html

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Re: Speeds at River Plate

Post by Dave Saxton » Fri Sep 26, 2014 1:57 pm

So the Exeter accelarated from 14 knots to 25 knots in 3 minutes while executing a 180* turn?
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Speeds at River Plate

Post by alecsandros » Fri Sep 26, 2014 2:46 pm

Dave Saxton wrote:So the Exeter accelarated from 14 knots to 25 knots in 3 minutes while executing a 180* turn?
The article says "Exeter was ordered to investigate at 6:14". She probably started accelerating at this time.

We know from British and German sources that Graf Spee spotted the cruisers before 6:00, and started accelerating , creating significant smoke. My guess is this smoke was visible from the cruisers significantly before 6:14.

Nonetheless, according to http://www.hmshood.com/ship/accelerationgraph.jpg, County class cruisers could accelerate from 15 to 25kts in 5 minutes and from 15 to 28kts in 10 minutes; from 15 to 30kts in 15 minutes...

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Re: Speeds at River Plate

Post by Dave Saxton » Fri Oct 24, 2014 12:55 pm

What were the max speeds of Ajax and Achillies?
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Speeds at River Plate

Post by alecsandros » Fri Oct 24, 2014 1:44 pm

Dave Saxton wrote:What were the max speeds of Ajax and Achillies?
during the battle probably 31kts.

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Re: Speeds at River Plate

Post by Dave Saxton » Sat Oct 25, 2014 3:20 pm

It works out that they got a bit more speed than that.
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Re: Speeds at River Plate

Post by aurora » Thu Nov 27, 2014 3:14 pm

With "clean" bottoms- I would say Ajax and Achilles could do 32kts max. Max Rated Speed=32.5 kts
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Re: Speeds at River Plate

Post by Tom17 » Sun Nov 30, 2014 9:37 am

With regard to the http://www.hmshood.com/ship/accelerationgraph.jpg,
The curves will be different for HMS Exeter and a 'County'
Although Exeter had about the same SHP (80 000), she's shorter (575' - 630') and lighter (8,400 - 9,800)
(figures are from Jane's fighting ships WW 2)
Tom

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