Rodney chase salvo

Michal Kopacz · Post by **Michal Kopacz** » Tue May 22, 2007 9:52 am

I am curious if Rodney "chase salvo" during battle with Bismarck. In my opinion it's wasting a time and has more influence on own fire control solution than accuracy of enemy fire. Of course it was often practice (like Piorun vs Bismarck for example) but in case if one opponents was interested in avoiding hits than scoring. Rodney's plot (taken from Brooks Warship article) looks quite straight:

but reading „Report of Proceedings” by Gatacre, who was Rodney's navigator at that time, I found statement that he advised captain to "chase salvo" and that was executed...

Orville H. Larson · Post by **Orville H. Larson** » Tue May 22, 2007 10:08 am

Well, it wasn't necessary for RODNEY to "chase salvos"--the threat from BISMARCK didn't last that long.

The British battlewagons cut loose at 0847. BISMARCK replied. The British didn't obtain a hit until 0902, when one of RODNEY's shells hit BISMARCK forward. BISMARCK's third salvo straddled RODNEY, but that was the closest she came to a direct hit on either of her antagonists. BISMARCK, remember, was making slow headway and steering an erratic course. Thus, she couldn't keep her guns bearing.

BISMARCK's gunnery control was shot to hell soon afterwards.

Michal Kopacz · Post by **Michal Kopacz** » Tue May 22, 2007 11:11 am

True, we know that now, but I think on Rodney they had different perspective. Per Gatacre he advised chase salvo after first straddle.

RF · Post by RF » Tue May 22, 2007 2:11 pm

I believe Rodney was altering course at the time of that straddle to bring all three turrets to bear.

paulcadogan · Post by **paulcadogan** » Tue May 22, 2007 7:29 pm

I wonder how well poor old Rodney could chase salvos given her sluggish helm! By the time she started to respond the next salvo would have been upon her....

Paul

Alatriste · Post by **Alatriste** » Tue May 22, 2007 7:55 pm

Sorry but what is "chase salvos"

paulcadogan · Post by **paulcadogan** » Wed May 23, 2007 3:13 am

Hi Alatriste,

This is the way I understand it....(if I mess up, others who know better please correct me...!!)

"Chasing salvos" is a method used in battle to reduce the chances of getting hit by the enemy. When a ship fires a salvo, its spotters observe the fall of shot in relation to the target and make corrections for range and line to try to obtain a straddle. If the target maintains its course and speed, eventually it will be straddled and very likely hit.

To confuse the enemy spotters the target ship could steam towards the relative position of a salvo that falls far away because the next "corrected" salvo will not fall in that location. Also, if a salvo falls close to the ship, course would be altered away, because the next one might be even closer or even hit.

Example: The first salvo falls 200m short of the ship. The ship alters course so that when the next salvo arrives it is 200m closer to the enemy. In this way the enemy's next corrected salvo will probably fall some distance over. The ship will alter course again and so on.

If a salvo straddles the ship, it will alter course to increase or decrease the range to avoid being straddled again or hit by the next salvo.

I would think that this process requires a very maneuverable ship to be effective. I think Ajax and Achilles did it vs. Graf Spee and probably avoided crippling damage that way. Hood could have done it too (if given the chance!), but it would have compounded her gunnery problems, given her old fire control system. Rodney might have had a hard time because she and Nelson were very ungainly on the helm. But who knows, maybe she tried...

Hope that helps! But as I said, others might know better...

Paul

RF · Post by RF » Wed May 23, 2007 9:15 am

Paul,

I think it is the other way round - steam into close falls of shot so the enemy overcorrects for the next salvo - and steam away from distant falls of shot so that the enemy undercorrects for the next salvo.

By steaming towards a distant salvo you head straight into the enemy correction of shot....

Bgile · Post by **Bgile** » Wed May 23, 2007 1:28 pm

The reason it's called "salvo chasing" is you head toward the last salvo's implact point. Paul's description is correct.

It does interfere with your own gunnery, and I think it's best use is when it is ok if both ship's gunnery is degraded, such as when the enemy has superior firepower and you need to escape or get closer. Of course, the process slows down your ship ...

Karl Heidenreich · Post by **Karl Heidenreich** » Wed May 23, 2007 2:13 pm

This is a very interesting thread, with valuable info, at least for me.

Thanks to all of you.

paulcadogan · Post by **paulcadogan** » Wed May 23, 2007 5:21 pm

Hi all,

I Googled "Chasing salvos" to check and what I found agrees with Bgile - going towards the last fall of shot because the next one will not likely be in the same place - unless it was on-target to begin with. Most of the specific references involve cruisers or destroyers under heavy or superior enemy fire.

Here's a quote from Dudley Pope's "Battle of the River Plate" Chapter 8:

..when the Graf Spee's gunfire had been getting unpleasantly close, (Captain Parry) had told Cowburn: "Alter toward the splashes, Pilot. That will probably upset his gunnery more than anything else we can do."

Cowburn had been playing his game skillfully - Captain Parry was later to attribute the Achilles apparent invulnerability to this - and as soon as the salvo had landed along the port side Cowburn had ordered a high speed turn to port.

The idea behind this was that the Graf Spee, spotting her own salvoes, would make an "up" correction for "shorts" and a "down" correction for "overs". By steering the Achilles toward the splashes, Captain Parry would always be steering away from where the second (and corrected) salvo would fall.

If a salvo falls on top of you, you need to get out of that position quickly or the next will likely fall on you again. So as long as you're not being straddled, you steam towards or "chase" the off-target splashes.

Have a great day!

Paul

Michal Kopacz · Post by **Michal Kopacz** » Thu May 24, 2007 7:58 am

I know that it's hard to image that such BB's manoeuvres have any effect to enemy fire (even that Bismarck fired about one round per minute at first stage duel with Rodney). ADM 186/349 (Progress in Naval Gunnery, 1938) says: "Altering course at high speed with full rudder causes so much falling off in gunnery accuracy that the amount of rudder used should be limited to the minimum necessary to achieve the tactical object"

But in other hands, per John Brooks:
"By zigzagging, Lion threw out opponents' fire for a short time and both Beatty and Chatfield recommended alterations of two points (one point at high speed) with small helm to this end. The former added:
This has often been practised and will in no way interfere with our gunnery."

RF · Post by RF » Thu May 24, 2007 10:24 am

paulcadogan wrote:Hi all,

..when the Graf Spee's gunfire had been getting unpleasantly close, (Captain Parry) had told Cowburn: "Alter toward the splashes, Pilot. That will probably upset his gunnery more than anything else we can do."

Paul

Note Cowburn's reply: ''I see that sir but I hope the enemy doesn't'' meaning that if the Graf Spee cunningly didn't correct its fall of shot....

paulcadogan · Post by **paulcadogan** » Thu May 24, 2007 3:49 pm

Lucky for the Achilles, the Graf Spee didn't!

I guess chasing salvos would work until your observant enemy figures out what you're doing, then watch out!

Alatriste · Post by **Alatriste** » Fri May 25, 2007 12:24 am

Thank you, I understand now what you are talking about.

I don't think Rodney "chase salvos" during the battle. They British wanted to close the range and hit Bismarck as soon as possible and "chase salvos" would only affect her own shooting.

But if you look at Bismarck plot it seems the Germans did "chase salvos". Just a joke, the Bismarck was out of control.