Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[tonyH]

Hello there,

I'm contemplating building a version of the French Arquebuse type destroyer (1900 or so) but I'm mystified for 3 reasons.

(1) There's a rather large bowsprit type thingy which could be a ram, a mine (except she'd blow her bows off), a bumper or a parking aid for le Capitaine! It's about the same diameter as the base of the mast and it appears to have a padded end, looking rather like a large match in profile.
(2) The single rudder is ahead of the 2 props - was this common practice?
(3) The props were staggered - the port one being ahead of the starboard one by a foot or so - why?. This is not a printing error 'cos the prop guards are also staggered to suit.

The photo shows the pointy thing.

Any ideas?

Tony

[andyn]

1) It apears to be a walkway of some sort
2) It isn't, and I can't imagine a model one would turn too well...
3) What you have found here is the world's first magic roundabout boat. When power is applied, it spins round in nice ever decreasing circles...

 

[tobyker]

A number of early torpedo boats had the rudders ahead of the props, split above and below the shafts. I dunno why the props were staggered - did they overlap? or if they were close together perhaps they created some sort of vibratory interference. However it might just be a french thing - like the renault 4 which had a longer wb one side that the other, so that the rear torsion bars could sit ione behind the other. The pointy thing is of course to mount the pin for the 1902 coupe maritime de bursting les ballons held off le Touquet, but alas no other nations turned up so it all feel rather flat.

[tonyH]

It's definitely a Pollux et Zebulon special!
The pointy thing is about 1ft square with a bumper end - no ropes or handrails. I tried to resize the plan but it wasn't having any of it so I can't show you. The props are well spaced and the rudder is well afore the props so it may just be one of those 'French' style things like excessive tumblehome.

Tony

PS Didn't you realise that the Renault 4 was built to compete in the Indy 500!

[warspite]

from some of the phot's viewed on the web, it appears some of this style of destroyer appeared to have a torpedo tube protruding through the bow, this devise appears to be pivoted on the deck and i would sumise (could be wrong) it is a derrick for lifting a torpedo on board the vessel, layed flat so as not obstruct the view when underway or add stress to the deck when upright, the 'matchstick' end being the pulley at the top of the derrick and has a canvas cover, would need to see more detail from above to see if a torpedo could be moved from front to back along the deck. what about seeing if any of the naval archive sources have information especially lower deck plans, maybe the torpedos were stored in the bow section.

[bogstandard]

The offset props might be to counteract the torque effect of the props, especially if they turned in the same direction.
 
Some of the German E boats had an enequal transom area, giving more bouyancy on one side, to keep the boat on a port/stbd even keel.

One fwd prop suggests that the ship would have a tendency to turn better one way than the other, so was given offset props to make it run in a straight line when under full power.


Bogs

[Niall]

On the offset propellers. The ship looks to have a very narrow beam. So the propellers might be too close together if they were side by side.

[tonyH]

Hello again,

Thanks sofar!

Tobyker and Niall are right about the props. I've checked further and the props overlap by about 15%. It seems quite ineffiient but the boats ran upto 30Kts so they cant have ben too bad.
I've also checked on the sections and there is nothing under the bow except storage space. The torpedoes were stored close to the tubes, amidships and aft, so I'm still trying to answer the matter of the pointy thing?
As far as the rudder location is concerned, this was one of the larger and faster classes, so it must have worked in more than just trials - odd.

Tony

[RickF]

Tony,

Ref "rudder forward of the prop", the following is from "Steam Picket Boats" by Stapleton:

The development of the torpedo as a weapon of defence led Mr White to consider a means for obtaining
increased manoeuvring ability in his boats, this being a very important factor in solving the problem of using
torpedoes with greater effect. Finally, in 1881, he decided that he had solved the problem and built a 42 foot
steam pinnace on speculation, fitting her with two rudders, one forward of the other, and cutting the deadwood
from under the stern until the boat would literally spin round like a top, gaining for her the semi-official name of
a “turnabout boat”. The larger, and main, rudder was situated abaft the propeller whilst the smaller one was
forward of the propeller which made her particularly handy when going astern At first the authorities were apt
to shake their heads over such a revolutionary idea, but as soon as she was tried and they realised her
superiority over the existing types and she was immediately brought into service and supplied to H.M.S.
Inflexible, which was then considered to be the last word in naval construction.

While it does not apply directly to the French TBD you are looking at, it does throw some light on the thinking behind it.

Incidentally, early Yarrow-built torpedo boats were built with a retractable bow rudder.

Rick

[tonyH]

Thanks for that Rick,

I can understand the White  'cunning plan' but this one has nothing aft of the screws and no bow rudder. There is just a single, normal size, unbalanced rudder well forward of the props.
I've been trying to reduce the size of the (tiff) plan but my computer says no so I can't post it, but its on the French MoD site as a free download.

Regards from Suffolk

Tony

[andygh]

Improved stewering when moving astern, none forward? Hmm, are you sure it was French? sounds more like an Italian design 

[tonyH]

I can put hand on heart and say that it's not Italian - this time!

I'm almost tempted to build to a bigger scale (current is at 1:96 to go with a battlecruiser project) to see if the system is actually effective, especially with the staggered screws but they did build 20 of the class, in two batches, and they did exceed their design speed etc. so they must work in some way but would it show up even at, say, 4-5 ft long?

As far as the 'prong' is concerned, on the plans it is shown as fixed on the deck and runs through a solid bow ring?

Tony

[derekwarner]

Hi all - staggered props in warships are relative to two engines in two different engine rooms ...however the actual centerline of each engine is the same axis....just the output shafts or speed reducers are port & stdb handed......you will also find that the AFT engine prop shaft will be at a different [greater] angle than the FWD prop shaft....just all to do with geometry & space .....Derek 

[tonyH]

Sorry Derek, not that simple.

In this case, the engines are on the same line across. The reason for the stagger is that the hull is so narrow that the prop diameters overlap by about 15% BUT one would have thought that there would have been a lot of wasted effort in cutting through 'dirty' water as far as the prop at the back is concerned.

Tony

[hopeitfloats]

try wikipedia. there are a couple of photos with the fat pointy thing on the arquebuse class ship.  photo taken on a slightly different angle to your photo but still hard to tell what it is.  may be of some help to  knowledgeable MBMer's.

[tobyker]

Have consulted my 1915 Jane's "the World's Warships" The one with the frontispiece showing the SMS Emden after action with HMS Sydney. There is not much standing above deck level apart from the after mast. Arquebuse is shown as a member of the 1902 Arbelete class. There is a photo of "Claymore" of the Coutelas class, completed 1906, which seems to have the same pointy thing arrangement. If you want a list of all ships in the classes, to aid research, let me know.

[tonyH]

Thanks all for the input.

I've (almost) come to the conclusion that the French designers were so lost without their ram bows when it came to destroyers that they substituted the telegraph pole with a boxing glove on the end. There would be a certain amount of logic to this in that opposition TB's were so narrow that a decent belt around deck height could have a fair chance of turning them over and so it was even possible that it was just an afterthought.

I'm still going ahead with a small one to see how effective, if atall, having the rudder, ahead of the props is and, of course, if anyone comes up with an alternative to the battering ram..................................

Thanks again

Tony

[Jimmy James]

Mystery bowsprit on early French Destroyers
Simply this, the vessels were so narrow forward that is wasn't practical to install hawser pipes for the anchor also many of them had bow torpedo tubes... So, to keep the chain cable clear they installed the "bow spirit" with a bow roller (the boxing glove) on the end) These days you find lots of modern yachts both power(Stink Pots) and sail use the same rig.
Freebooter

[Jimmy James]

Tony
On the subject of rudders being forward of the prop's almost all modern submarines rudders are forward of the prop.   It's a matter of balance and the fact that the rudder on the torpedo boats would be in clear water forward of the props and so would get a better grip for turning WHEN the v/l was underway at speed... also these v/l's were very narrow back aft and it might not have been practical to have the rudder yoke aft of the props....
British T/B & TB D's of the same vintage often had transom hung rudders but these were vulnerable to weather and battle damage this might be the French answer to this.... No matter what steering arrangement they used long narrow ships like this would have been a nightmare to maneover in tight quarters and would have had a turning circle like a supertanker on a bad day
 Freebooter

[tonyH]

Thanks JJ.

As far as the rudder placement is concerned, I'm sure you're right BUT there is still a question regarding the target subject. The build drawings show that the anchors are taken from P & S locations aft of the bow. The pointy thing is, literally, a heavy pole with a padded end.

I'm still going through all the class drawings on the Ministiere de Marine site but they all exceed the Forum rules (bow plans are 270K) and don't want to be resized so I can't show you what I mean but the more I look at, the more the b****r looks like a battering ram.

Tony

[Jimmy James]

Tony
I sent a copy of the picture you posted to a very oldfrend he's 102 years old ex RN ex shipwright He says thats what the "Bowsprit" was used for and that it (Bowsprit ) could have two or three sheeves set into the end to take the cable but as was the norm in those days the anchor was catted and stowed on the deck and that there was allways a heavy davit on the foc'le to house the ancor
Freebooter

[andygh]

Just came accross this photo, it says it's a japanese boat??

[tonyH]

Hells Teeth Andy, that's definitely a boxing glove - even with a separate thumb!

JJ, I'm having a problem logging into the French site but I've got a plan/section of the bow and anchor areas. It's too big to put on the forum but I'll try a pm so please let me know if you receive it. If you do, and want further info let me know and I'l try to send the main layout plan.

Tony

[tobyker]

On the japanese boat, it must be something to do with loading the bow torpedo tube - but your french Contre-torpilleur didn't seem to have one. Strange.

[Colin Bishop]

I've had a look in my 1914 Jane's Fighting Ships and it seems that all the French "destroyers" had a bowsprit around the turn of the century. In some cases it was obviously just a spar while in others you have something a bit more substantial with the "boxing glove" affair. However, some had bow torpedo tubes and some did not. I reckon the bow tubse would have been loaded internally and that the spar was indeed to do with handling the anchor as previously mentioned. It could never have been any sort of battering ram as anything of that nature would have been carried lower down where it would have been supported by the hull proper.

Intriguing all the same though.

Colin