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auto gearboxes in boats like a DUKW or stolly?


tankmaniac

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Which reminds me - ALL the FV-600 series vehicles had the indicator lines at some point in their lives on the hubs - yet I hear no word of complaint about Saracens and Saladins.... :???

 

Wasn't the Stalwart the only one with the No Spin centre diff though?

So the only one with permanent Six wheel drive, and hence the problems on tarmac.

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The No-Spin centre diff is not a bad bit of kit - it works by locking up when one side tries to go faster (as in lost traction on one side). But when one side wants to go slower (as in making a left turn where the inside set of wheels is being slowed down) the diff allows it to do so.

 

Does the Stalwart have one of these? If so the only real issue is the fact that all 3 wheels on each side are locked up. Older trucks with no inter-axle diff had two on each side locked together, so from an engineering design aspect it wasn't that different!

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...Which reminds me - ALL the FV-600 series vehicles had the indicator lines at some point in their lives on the hubs - yet I hear no word of complaint about Saracens and Saladins.... :???

 

To some extent that could be due to weight, The laden weight of Saracen was 10.17 to 10.7 Tonnes depending on role, The Saladin Mk2 was laden at 11.6 Tons, But Fv622 Stolly was 14.48 and FV623 Artillery Limber was 15.6 tons.

 

The extra weight obviously locks the wheels to tarmac or concrete move effectively, than is the case with the lighter Alvis models .

 

It may just be that the lighter models could spin a wheel to unwind the transmission, but the extra weight of Stalwart prevented this from happening.

 

In any case the extra weight (almost 50% heavier for the Limber) means Stalwart is harder to propel, the rolling restistance being much graeter, and therefore the transmission is loaded to 150% of Saracen. (which was probaly not that good an idea!)

Edited by antarmike
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<snipped>

In any case the extra weight (almost 50% heavier for the Limber) means Stalwart is harder to propel, the rolling restistance being much graeter, and therefore the transmission is loaded to 150% of Saracen. (which was probaly not that good an idea!)

 

There is a 2 ton weight difference (laden or unladen - both have a 5 ton payload) between the 622 and 623/4 version - unless maths has changed since I were a lad that's hardly 50% difference! :)

 

Again if the Saracen was 10 tons and the limber/REME variant of the Stalwart was 15 tons - that is a 50% overload according to the math I were taught..... :):)

 

Biggest issue I know of regarding the extra weight- and perhaps Paulob1 can add to this - is the extra 2 tons is sat on top of the first two pairs of road wheels making the steering system work harder and causing a pronounced "nose down" attitude when swimming.

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To some extent that could be due to weight, The laden weight of Saracen was 10.17 to 10.7 Tonnes depending on role, The Saladin Mk2 was laden at 11.6 Tons, But Fv622 Stolly was 14.48 and FV623 Artillery Limber was 15.6 tons.

 

 

 

How often was a Stalwart seen driving on the road loaded? Most of their life they would run around unladen, especially now in private ownership. A lot of the transmission problems we encountered working on in-service ones, was tracta joints. The difference between the Saracen and Saladin to the Stalwart is that the former are running around at pretty much max weight, only crew and ammo to add on to basic vehicle weight. The suspension on a Stalwart is so set that when the max load is onboard, the horizontal view of the drive shafts is just slightly sloping down hill as on the armoured family. Unladen the drive shafts work at quite an acute angle, which with wind up does not help. I remember one in service with a RE training unit, which was suffering problems and we set the torsion bars so that the drive lines were in a loaded position. I also did this to a private owners Stalwart many years ago when he was experiencing similar problems.

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There is a 2 ton weight difference (laden or unladen - both have a 5 ton payload) between the 622 and 623/4 version - unless maths has changed since I were a lad that's hardly 50% difference! :)

 

Again if the Saracen was 10 tons and the limber/REME variant of the Stalwart was 15 tons - that is a 50% overload according to the math I were taught..... :):)

 

Biggest issue I know of regarding the extra weight- and perhaps Paulob1 can add to this - is the extra 2 tons is sat on top of the first two pairs of road wheels making the steering system work harder and causing a pronounced "nose down" attitude when swimming.

 

Laden Weight for 622 and 623 , Saladin and Saracen quoted from MVEE handbook.

 

The almost 50% difference I mention is between Saladin APC mk2 FV603(B) laden weight 10.17 Tonnes and FV623 Limber laden weight 15.6 Tons laden.

 

Stalwart 623 is 5.43 Tonnes heavier than this Saracen APC.

 

Stalwart 623 laden is therefore 53.4% heavier than this saracen laden. (about half as heavy again)

 

or to put it another way Stalwart 623 is 153.4% the weight of this Saracen. (about one and a half times the weight)

 

Rolling resitance is roughly proportional to weight.

 

Therefore rolling resistance of FV623 Stalwart limber will be approx 150% rolling resistance of Saracen.

 

The force needed to overcome rolling restance is roughly proportional.

 

The transmission in FV623 limber is therefore (roughly) loaded to 150% of the transmission in Saracen. ie it will have to work 50% harder.

 

Please re-read what I initially wrote, I think it is clear I am comparing the Stalwart LImber with Saracen. If you still do not follow the figures I can give you some personal maths tuition via PM's

In any case the extra weight (almost 50% heavier for the Limber) means Stalwart is harder to propel, the rolling restistance being much graeter, and therefore the transmission is loaded to 150% of Saracen. (which was probaly not that good an idea!)

I can't see what is wrong with my maths.

Edited by antarmike
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How often was a Stalwart seen driving on the road loaded? Most of their life they would run around unladen, especially now in private ownership. A lot of the transmission problems we encountered working on in-service ones, was tracta joints. The difference between the Saracen and Saladin to the Stalwart is that the former are running around at pretty much max weight, only crew and ammo to add on to basic vehicle weight. The suspension on a Stalwart is so set that when the max load is onboard, the horizontal view of the drive shafts is just slightly sloping down hill as on the armoured family. Unladen the drive shafts work at quite an acute angle, which with wind up does not help. I remember one in service with a RE training unit, which was suffering problems and we set the torsion bars so that the drive lines were in a loaded position. I also did this to a private owners Stalwart many years ago when he was experiencing similar problems.

 

I very goodpoint, which had't really occured to me.

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Laden Weight for 622 and 623 , Saladin and Saracen quoted from MVEE handbook.

 

The almost 50% difference I mention is between Saladin APC mk2 FV603(B) laden weight 10.17 Tonnes and FV623 Limber laden weight 15.6 Tons laden.

 

Stalwart 623 is 5.43 Tonnes heavier than this Saracen APC.

 

Stalwart 623 laden is therefore 53.4% heavier than this saracen laden. (about half as heavy again)

 

or to put it another way Stalwart 623 is 153.4% the weight of this Saracen. (about one and a half times the weight)

 

Please re-read what I initially wrote, and if you still do not follow I can give you some personal maths tuition via PM's

 

I can't see what is wrong with my maths.

 

I'm just emulating pendantic mode.:) Reading this:

 

In any case the extra weight (almost 50% heavier for the Limber) means Stalwart is harder to propel,

 

to me read like you were saying the 623/624 is 50% heavier than the 622 - which it manifestly isn't! :)

 

Reading this:

 

and therefore the transmission is loaded to 150% of Saracen. (which was probaly not that good an idea!)

 

to me read like you were saying the overall weight of the 623 was 150% that of the Saracen. Which again it isn't - it's 50% greater - to be 150% greater would have the 623 weighing in at around 25 tons. Transmission load on the Saracen is 10 tons, on a 623/624 Stalwart is 15 tons, difference is 5 tons which is 50% of 10 tons.

I'd fully concur with the last sentiment though!! :)

 

 

I very goodpoint, which had't really occured to me.

 

It occurred to me - and most other owners I know - lowering the ride height to the laden position takes a lot of stress/strain (call it what you will ) out of the drive train. It was one of the first things Richard Notton told me to check when I bought mine!

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150 apples are 50 apples more than 100 apples,

150 apples is 50 % more than 100 apples

but 150 apples are also 150% of 100 apples.

 

50% of 100 is 50

100% of 100 is 100

150% of 100 is 150

 

150% of 10 tons is 15 Tons.

 

to me read like you were saying the overall weight of the 623 was 150% that of the Saracen. Which again it isn't

 

 

sorry but yes, the weight of the Stalwart limber IS 150% of the weight of Saracen.

 

{If something weighed 101% of the weight it would be very slightly heavier, if it weighed 99% of the weight it would be slightly lighter.}

 

 

There is a big difference in quoting what the difference between two things is, as a percentage of the smaller figure, rather than to quote by what percentage one figure is larger than another.

 

 

I said "and therefore the transmission is loaded to 150% of Saracen." I did not say "it is loaded by an extra 150%."

 

What I said IS correct, what you think I said is incorrect.

 

 

If saracen takes 100 units of force to move it, FV623 will take roughly 150 units of force to move it, or an extra 50 units of force. 150 units of force is 150% of 100 units of force.

 

 

If I had said,

"In any case the extra weight (almost 50% heavier for the Limber) means The Limber is harder to propel,"

rather than what I actually said which was

"In any case the extra weight (almost 50% heavier for the Limber) means The Stalwart is harder to propel,"

then I could understand your misinterpretation, but since I am clearly comparing Stalwart in general to something else, rather than comparing the limber to something else. Especially since the same sentence finishes with "and therefore the transmission is loaded to 150% of Saracen. "

I feel this makes it more than clear that I was comparing Saracen to Stalwart, rather than comparing FV622 with FV623.

 

In English something written in brackets (such as this) within a sentence, is optional, the sentence can be read without reading the brackets, since what is contained within those brackets merely provides extra information that may or may not be read depending upon your mood and how lazy you want to be. Leaving out something in brackets may lose information but it doesn't alter the basic structure and meaning of the sentence.

Hence this same sentence can read as "In english something written in brackets within a sentence, is optional, the sentence can be read without reading the brackets, since what is contained within those brackets merely provides extra information that may or may not be read depending upon your mood and how lazy you want to be." I have ommited the brackets and the sentence means just the same.

 

The sentence "In any case the extra weight (almost 50% heavier for the Limber) means The Stalwart is harder to propel," can therefore be reduced , by leaving out the brackets, to "In any case the extra weight means The Stalwart is harder to propel," It is absolutley plain english and not open to misinterpretation. I am talking about Stalwart in general, compared to Saracen.

 

I do not understand how you can have got me wrong.

Edited by antarmike
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Is it pantomime season yet?

 

Oh yes it is, Oh no it isn't, Oh yes it is?

 

sorry , but I'm bored,I have said it all , please read post#59 very carefully and talk it over with someone who is proficient in Maths and English before rushing into a counter post, please.....

Edited by antarmike
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to me read like you were saying the overall weight of the 623 was 150% that of the Saracen. Which again it isn't - it's 50% greater - to be 150% greater would have the 623 weighing in at around 25 tons.

 

Oh go on just on more pantomime moment then, since you mentioned 25 ton vehicles, lets think about that for a second or two.

 

50% of 100 os 50

100% of 100 is 100

150% of 100 is 150

250% of 100 is 250

 

250% of 10 is therefore 25

150% of 10 is therefore 15

 

If the Saracen weighs 10 tons,

then a vehicle weighing 25 tons would be 250% of the weight of Saracen , (and I certainly never mentioned 250%!!)

or its weight would be greater than saracen by 150% or 15 Tons.

 

Saracen weighs 10 tons, a vehicle that is 150% of the weight weighs 15 tons,

but a vehicle weighing 25 tons is 250% of the weight (two and a half times heavier.)

 

when you buy something that costs £100 ex VAT then the VAT will be added at the rate of 15%

 

that works out as £15 VAT to pay on top of (or extra to) the ex vat price

 

If the Ex vat price is £100, then the EXTRA you pay in VAT is £15 or 15% of £100.

 

The Price you pay including VAT is £115. This 115% of the ex VAT price.

 

£115 is not 15% of £100. 15% of £100 is only 15 Pounds.

 

When I buy £100 ex vat of goods from the Screwfix trade catalogue, I would like to pay 15% for them ie £15, but I have to pay 115% or £115, which is the inclusive of VAT price stated in the DIY version of their catalogue.

 

The weight of Saracen is 10 tons,(the ex Vat price) the Extra weight of Limber (the VAT )is 50% of 10 Tons, ie 5 tons.

 

The weight of Limber (the price including VAT) is 15 tons. This is 150% of weight of Saracen. 50% the weight of Saracen is only 5 Tons.

Edited by antarmike
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<snipped>

I do not understand how you can have got me wrong. Does your College also do basic English?

 

Try asking the University of Liverpool - they are the ones who dealt with the Masters degree in IT/Relational Databases!

 

Or try the EITB and Ford Motor Company who dealt with the accredited apprenticeship in Toolmaking.

 

I've no objection to a civil/friendly discussion on things but as you seem to want to resort to personal insults now then I am out of here.

 

You have your views, I have mine.

 

End comm.

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sorry , but I'm bored,I have said it all

 

Sorry, but I got bored before you :yawn: Though it is fun to see those who like to wind others up, ending up winding themselves up.

 

And just for a bit of light relief, here's a sign seen today in the window of an Explorer:

Sign.jpg

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my tracta joint went once about three years ago....wasn a bad job to fix and a lot better than the bevel box going...i have lowered my torque arms to keep them more even as i rarely travel with any load, (took 5 tons of soil once and that was some tough journey...)

 

240 bhp is not bad for hauling 15 tons or there abouts...most 7.5 toners run with 150 bhp and most modern 16 toners around 210-250 bhp...so 240 in 1960 must have seemed like heaven sent...my zil 131 which loads up to 11 tons and has just 150 bhp and the ural 375 d which will load up to around 14 tons has just 180bhp...so dont think the stolly is really that short of power its just all that drive train friction....

 

Mind you all academic now my engine has gone pear shaped...anyone got a good block they can let me have...still gotta love these things though...think i will buy two more, one I am going to strip of everything I can, and turn it into an offroading toy, minimum weight and traget weight being under 5 tons, is it possible i wonder...) and the other will be a hauler for the off road toy with winch only, and likely I will disengage the front bevel boxes and onyl drive on two sets of wheels...al depends upon cash but i have the toys in sight...just got to agree the deals...

 

My current one will stay for site work and show work, shes going desert sand colour this time round...

Edited by paulob1
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Try asking the University of Liverpool - they are the ones who dealt with the Masters degree in IT/Relational Databases!

 

Or try the EITB and Ford Motor Company who dealt with the accredited apprenticeship in Toolmaking.

 

I've no objection to a civil/friendly discussion on things but as you seem to want to resort to personal insults now then I am out of here.

 

You have your views, I have mine.

 

End comm.

 

To question my maths a second time after I had carefully explained it , and then add the comments to the effect that I am obviously wrong, is in itself an insult. To say it is "manifestly wrong" suggests that everyone looking at it knows it is wrong because it jumps out at you as being wrong.

 

I have A level Maths, and I lectured in a College, teaching Engineering to Engineering Btec students, which involves constant use and understanding of percentages, and precise technical language, for a 17 year period. No one has ever before said that my understanding of percentages is obviously wrong.

 

I am sorry but it is most clear to me that you do not understand percentages, nor can you examine a simple english sentence to extract its correct meaning.

 

I have laboured to explain it, but I seem to have failed.

 

I feel that maybe someone with special training in remedial Maths and English, might be better equiped to explain the principles, that is why I recommend that you sees what courses are available at the local college. I have no personal bitterness towards you, I am not trying to humiliate you, but you keeps coming back saying I am not only wrong, but that it is obvous that I am wrong. I believe I am right.

 

What is your view on my statements? Am I wrong with my Maths? Was my statement open to mis-interpretation. I think not? Do you think that an apology to me might be in order, when you have tried so hard to make my maths look stupid? What are your credentials for telling me about percentages?

Edited by antarmike
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To question my maths a second time after I had carefully explained it , and then add the comments to the effect that I am obviously wrong, is in itself an insult. To say it is "manifestly wrong" suggests that everyone looking at it knows it is wrong because it jumps out at you as being wrong.

 

I have A level Maths, and I lectured in a College, teaching Engineering to Engineering Btec students, which involves constant use and understanding of percentages, and precise technical language, for a 17 year period. No one has ever before said that my understanding of percentages is obviously wrong.

 

I am sorry but it is most clear to me that you do not understand percentages, nor can you examine a simple english sentence to extract its correct meaning.

 

I have laboured to explain it, but I seem to have failed.

 

I feel that maybe someone with special training in remedial Maths and English, might be better equiped to explain the principles, that is why I recommend that you sees what courses are available at the local college. I have no personal bitterness towards you, I am not trying to humiliate you, but you keeps coming back saying I am not only wrong, but that it is obvous that I am wrong. I believe I am right.

 

What is your view on my statements? Am I wrong with my Maths? Was my statement open to mis-interpretation. I think not? Do you think that an apology to me might be in order, when you have tried so hard to make my maths look stupid? What are your credentials for telling me about percentages?

 

your maths were right to me...still like my stalwart thought even if its a mathematical anomaly or not...:)

 

right or wrong, to me it appeared that you did get into this thread in a way that was worded to goad people into an argument...you succeeded.:shocked:

 

Hey ho, each to their own. Still have a great liking for my stolly and any I see...good or bad...even my broken one boo hoo:-(

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and the other will be a hauler for the off road toy with winch only, and likely I will disengage the front bevel boxes and onyl drive on two sets of wheels...al depends upon cash but i have the toys in sight...just got to agree the deals...

 

Are you sure that you want to put all the 240bhp through just two bevel boxes and tracta joints? Especially if it's towing another one.

 

By the way I'm with Mike on the maths.

 

Anyone care to ask Neil what percentage of it's worth Neil has spent on his Stalwart?

Lights blue touch paper........

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Are you sure that you want to put all the 240bhp through just two bevel boxes and tracta joints? Especially if it's towing another one.

 

By the way I'm with Mike on the maths.

 

Anyone care to ask Neil what percentage of it's worth Neil has spent on his Stalwart?

Lights blue touch paper........

 

Too much mate - thats all I'm saying!! :):) And it still ain't over yet - they are like a bug though - once bitten impossible to lose.

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Are you sure that you want to put all the 240bhp through just two bevel boxes and tracta joints? Especially if it's towing another one.

 

By the way I'm with Mike on the maths.

 

Anyone care to ask Neil what percentage of it's worth Neil has spent on his Stalwart?

Lights blue touch paper........

 

yes I have thought about that but know a few people who have done it with success and no problems, biggest issue with the tractas and the bevel boxes seems to be jerk loads, ie trying to pull out a stump or recover another vehicle dangerous activities...the bevel boxes are fine with a good load of power and if I removed the tracta units from the front then likely rolling resitance would be a good deal less...she would be better to handle and steer...with me its more like an idea than a reality thought, i have way too many projects to even get near to this one...I will likely just buy a proper transporter for the toys...I just think the stollys are so good and there must be a way to make them even more fun and the reduced weight model is a real possibility...

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The need to alter the torsion bar height to suit periods of running empty and having to reset them, to carry a full load, is not good.

 

As I say there are design weaknesses in Stolly design.

 

If Stolly can't cope with running empty, then there should be a central mechanism to alter the Torsion bars, maybe this even should have been automatic, controlled by a load sensor.

 

As it is, saying the Stollie doesn't have a transmission problem because you can reset the torsion bars when it is empty, is really saying yes, there is a problem, which should have been solved at the start. A problem which should have allowed the Stalwart to run loaded or empty, without a lot of messing around.

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These trucks were removed from the army because of their complexity and age...now you think adding more complexity and weight to them would help, nah dont think so would not be in the design brief...and was not needed...the fact that we lower the torsion bars is sensible practice not an essential need...I did mine a few weeks ago after 7 years as normal...makes her look much smaller now she is lowered by 4 inches..

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yes I have thought about that but know a few people who have done it with success and no problems, biggest issue with the tractas and the bevel boxes seems to be jerk loads, ie trying to pull out a stump or recover another vehicle dangerous activities...the bevel boxes are fine with a good load of power and if I removed the tracta units from the front then likely rolling resitance would be a good deal less...she would be better to handle and steer...with me its more like an idea than a reality thought, i have way too many projects to even get near to this one...I will likely just buy a proper transporter for the toys...I just think the stollys are so good and there must be a way to make them even more fun and the reduced weight model is a real possibility...

 

Did you see the sand coloured one at W&P last year Paul - that had air lockers on the front and rear drive shafts so that it ran in 2 wheel drive normally (centre wheel stations) and then either 4 or 6 wheel drive could be selected from the cab. A nice piece of engineering work.

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The need to alter the torsion bar height to suit periods of running empty and having to reset them, to carry a full load, is not good.

 

As I say there are design weaknesses in Stolly design.

 

If Stolly can't cope with running empty, then there should be a central mechanism to alter the Torsion bars, maybe this even should have been automatic, controlled by a load sensor.

 

As it is, saying the Stollie doesn't have a transmission problem because you can reset the torsion bars when it is empty, is really saying yes, there is a problem, which should have been solved at the start. A problem which should have allowed the Stalwart to run loaded or empty, without a lot of messing around.

 

 

Is it probable that a large percentage (near 100% but maybe slightly less) of Stalwart evaluation testing was carried out off road with no thought to on-road use?

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Did you see the sand coloured one at W&P last year Paul - that had air lockers on the front and rear drive shafts so that it ran in 2 wheel drive normally (centre wheel stations) and then either 4 or 6 wheel drive could be selected from the cab. A nice piece of engineering work.

 

Yes they are a damn good piece of engineering work...I just want my stolly back and working now...with or without its flaws...

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Is it probable that a large percentage (near 100% but maybe slightly less) of Stalwart evaluation testing was carried out off road with no thought to on-road use?

 

To a degree but it was tested at mira and other locations...it makes interesting reading but alvis did short change the army,they could have done a better job...mike is not...but it is still a quirky but lovable truck...however the major trial was with a cheiftain ceturion and saracen...the saracen was stuck all the time, the fully laden stolly recovered it every time and never got stuck...it even pulled out a chieftain and towed it 250 yads before its tow hook shattered..the army liked it then..

 

but it was a flawed genius...and still really unrivalled today.

 

If we did it again it would be a good deal different i think...on this Mike is surely right but it isnt and the stalwart is...long live the stalwart

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