'S' tank v Chieftain etc

Started by Big Insect, 17 June 2022, 11:31:35 PM

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Big Insect

This is to 'divert' the conversation running on the List thread over to a separate dedicated one.

As previously stated by others, we have a limited combination of two 6's to work out our Hits v Saves in CWC and that gives us challenges around the granularity we are able to achieve.

So looking at CWC-I:
Swedish 'S' tanks were Hits:4 / Saves:5 (cover category increased by 1 in all situations)
Chieftain Mk.2/3 to Mk.11 were Hits:6 / Saves:3

In CWC-II the stats are:
Swedish 'S' tanks are Hits:4 / Saves:5 (Low Profile - so -1 d:6 all round)
Chieftain Mk.2/3 to Mk.11 were Hits:6 / Saves:3

So no change between the two lists.

The challenge with the 'S'tanks is that there are no obvious like-for-like comparisons.
Looking at contemporary tanks, such as: AMX-30 / Chieftain / Leopard 1 / M60 Patton / T-62 / T-64 / T-72 / TR-85/ Type 69/79 / Type 74 and the Vijayanta - a 5/4 for a T-72 compared to a Chieftain at 6/3 is (IMHO) not realistic.

Also, the challenge with downgrading the Chieftains is that this then has a knock-on effect down the chronological 'history' of British tanks - so if Chieftains were to be 6/4 (for example) do we downgrade Centurions to 5/4 for Mk.6/2,Mk.11, Mk13 and then Mk.2, Mk.3, Mk.5/1 to 4/4 - which does not do them justice against other contemporary tanks. That also then has a knock-on back to Comets and Cromwell VII etc.etc.

If you then apply the same logic to attempt to create a comparative set of protection for the contemporary Soviet tanks the problem is compounded and that then applies to US, French and Chinese tanks as well.

Also - at one end of our 6 / 6 Hits v Saves equation I have that M1 Abrahams (on a 6/2) and at the other (believe it or not) we have the T-26 (yes the Spanish were fielding T-26s until 1950) or the M3 Stuart (used by the Portuguese and Indians, amongst others, until the early 1970s) which in theory should probably down to a 2/6, but we give them a 3/6 or we start running into negative points costs! (not quite but almost).

BTW - you 'tinker' with this system at you peril !!!

I will certainly look at info and data on the 'S' tank but I suspect that test data around munition effectiveness in ideal test conditions, would put a lot of tank armour under considerable pressure.

Thanks
Mark



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Lord Kermit of Birkenhead

Major  problem lies in tank design and internal structure. The shape of the S tank and also the Cheiftain glasis make it hard to get a "sticky" hit, rounds tend to bounce off. There is also the problem of internal design of the vehicle. Soviet tanks suffer from poor internal design, with ammunition off stowed above the turret ring as opposted to western practice of having it below. Also certainly Cheiftain and Challenger have their rounds stored in fire proof bins.

Next problem is hitting the target and this is mainly caused by target location and movement. Tank guns are inherently accurate - 2m drop in 3000m is quoted for the L7/M68 with Sabot. However allowing for deflection and spotting introduce errors. Target ranging has vastly improved with the introduction of laser rangers, prior to fitting Cheiftains with TOGS they could'nt engage at over 1800m as that was the range at which the Ranging Gun trace burnt out. OPtical ranging was longer ranged but soviet steroscopic rangers were less accurate whilst the coincidence rangers were difficult to use.

Moving on to armour - I'm using Chadwick's Gulf War Handbook for these figures but they feel accurate. First figure is for solid shot protection, second for HEAT. HESH is not covered.

M1A1 -            600/1300mm
M1 -              400/1000mm
Challenger 1      500/800mm
Cheiftain Mk5    400/400mm
M-84              250/250mm    (Yougslav T72 clone)
M60A3 with ERA    250/500mm
AMX-30B2          180/180mm - Leo1 about the same
AMX30            150/150mm
T72M1            400/550mm    HEAT value is an educated guess with ERA
T72G              350/350mm
T-72B            250/250mm
T62/55 Type59    200/200mm    If ERA the HEAT value could be about 500mm



That should give a good comparison but am afraid it does not include the S tank. The British army did test 3 of them and found them not suitable for their role, they also wrote one off.
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HogansHeroes

The Swedes for their part, had some choice words to say about those tests and British gunnery in general!

National bun fights and the Chieftain aside. A key question is how should the S Tank be modelled within the constraints available?

Currently, it is modelled as having WW2 hit/save values (4 hits, 5 save), but with the low profile and dozer blade abilities.

Now, I am not clear if this is a special low profile ability unique to the S-Tank that applies all the time or the standard low profile ability that only applies in certain situations as per page 7 of the rules (e.g. if in a low or high area terrain feature etc.). The Swedish army list seems to imply it applies all the time (but this contradicts the rules).

If it is the latter (only applies in certain situations), then the S-Tank is okay for defense, but worse than a T-54 in the open at medium range and lower. This seems a little bit off.

I would be tempted to increase the save value of the S-Tank to 4 (to reflect the highly sloped armour and superior reversing abilities that allows it to keep the front facing the enemy easier). The points would need to increase too.

You could increase the hit value too, but with low profile and dozer blades, this could make the S-Tank too powerful in defense? I feel some in game testing might help find the right balance here (I will give it a go, when I have time).

As mentioned, should the S-Tank speed be decreased? Its off-roading abilities were apparently poorer than the Centurion.

Big Insect

19 June 2022, 10:49:37 PM #5 Last Edit: 19 June 2022, 10:57:25 PM by Big Insect
QuoteThe Swedes for their part, had some choice words to say about those tests and British gunnery in general!

National bun fights and the Chieftain aside. A key question is how should the S Tank be modelled within the constraints available?

Currently, it is modelled as having WW2 hit/save values (4 hits, 5 save), but with the low profile and dozer blade abilities.

Now, I am not clear if this is a special low profile ability unique to the S-Tank that applies all the time or the standard low profile ability that only applies in certain situations as per page 7 of the rules (e.g. if in a low or high area terrain feature etc.). The Swedish army list seems to imply it applies all the time (but this contradicts the rules).

> that is correct it is automatically 'low profile' all the time - from all around. If you compare it to other contemporary 'turretless' AFVs - it is generally a lot smaller, lower in overall height and has a much lower silhouette and profile.

If it is the latter (only applies in certain situations), then the S-Tank is okay for defense, but worse than a T-54 in the open at medium range and lower. This seems a little bit off.
> see above - that is not the case  :)

I would be tempted to increase the save value of the S-Tank to 4 (to reflect the highly sloped armour and superior reversing abilities that allows it to keep the front facing the enemy easier). The points would need to increase too.

> I am very open to that as an idea

You could increase the hit value too, but with low profile and dozer blades, this could make the S-Tank too powerful in defense? I feel some in game testing might help find the right balance here (I will give it a go, when I have time).

> Great idea - much appreciated. I rarely get to run my Swedes out these days - usually against my Soviet Murmansk Division

As mentioned, should the S-Tank speed be decreased? Its off-roading abilities were apparently poorer than the Centurion.
 
> as is borne out by the report below. Although that seems to imply that it is unfirm ground rather than off-road more widely and I suspect that on hard ground it might have faired quite well. The shorter track-base issue is interesting. As I suspect that this is a weight to track length ratio thing, as smaller, lighter vehicles, such as Scorpions, Wiesel's etc. seem to do ok on soft-going.


Apologies for the delayed reply - got distracted on another post thread.
Thoughts in-line in-bold above ... but I also thought I'd post this extract from Wiki about the 'S' tank performance tests, which I think paint a much more rounded/balanced picture of its comparative performance

"The Stridsvagn 103 never saw combat and so its design remains unproven. However, for its intended role in the 1960s, it had numerous advantages. In 1967, Norway carried out a two-week comparative observation test with the Leopard 1 and found that, with closed hatches, the 103 spotted more targets and fired faster than the Leopard while the situation was reversed when operating with hatches open.

In April to September 1968, two 103s were tested at the British armour school in Bovington, which reported that "the turretless concept of the "S"-tank holds considerable advantage over turreted tanks".

In 1973, the BAOR tested the 103. British crewmen received six weeks training and the vehicles were serviced by Swedish engineers. Over nine days of manoeuvres alongside the Chieftain tank, availability never fell under 90% and the final report stated, "It has not been possible to prove any disadvantage in the "S" inability to fire on the move."

In 1975, two 103s were tested at the American armour center at Fort Knox. The trial demonstrated that the 103 fired more accurately than the M60A1E3, but on an average 0.5 seconds more slowly.

In comparison with the Centurion, the shorter track of the Strv 103 meant it performed worse on soft ground (mud and snow), and its trench taking and vertical obstacle capabilities were also significantly lower: where the Centurion climbed a 100 cm wall, the 103 was barely able to climb an 80 cm wall. On hard terrain, the 103 on the other hand was far more manoeuvrable."

So a mixed bag overall, but not damning.
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sultanbev

20 June 2022, 11:12:26 AM #6 Last Edit: 20 June 2022, 11:26:45 AM by sultanbev
FWIW
these are the maximum (usually turret) armour values I've used successfully for over 30 years, the hulls are lower usually
M1A1 -               46cm Chobham
M1 -                 40cm Chobham
M1A1HA               51cm DU-Chobham
M1A2                    71cm DU-Chobham
Challenger 1         46cm chobham
Challenger 2        70cm Chobham
Chieftain Mk1-2      28cm
Cheiftain Mk3-10     39cm
Chieftain Stillbrew  49cm ceramic layer (turret only)
M48A1-A3             23cm
M60A1                26cm
M60A1 with ERA       31cm ERA
AMX-30B2             24cm (turret only)
AMX30                16cm
T-72M1               36cm ceramic layer         
T-72 monkey model    28cm             
T-72B                42cm ceramic layer         
T-62                 24cm
T-55                 20cm
T-64A                33cm ceramic layer
T-64B                37cm ceramic layer
Strv-103B S-Tank      38cm
M84 Yugoslav  32cm

Although the armour type is more important than the thickness in terms of being knocked out. Even if the figures are not quite correct, they will be a good relative guide.

sultanbev

The Strv-103 has cross-country speed 25kmh, which is pretty much a universal standard, and road speed 50kmh, so just average speed all round. Mobility as apposed to speed is much more variable, as per every tank in differing terrain types.

The 105mm L74 gun on the S-tank has the same penetration as the Centurion but at about 800m further out. eg
M62 APDS in Centurion: 30cm/100m/90*, 24cm/1500m/90*
M62 APDS in S-Tank: 35cm/100m/90*, 30cm/1000m/90*; 24cm/2250m/90* or 28cm at 1500m/90*

Accuracy wise the 105mm L7 APDS is effective range* 2000m, 105mm L74 APDS 2250m ish, with optical sights
with laser ranging 2250m and 2500m respectively
with IFCS and M111 FSAPDS the S-tank has 2750m effective range

* Effective Range = 70% hit chance.

Whether that data alters anything is up to the writers, but ammunition for your thoughts at least.
Mark

Lord Kermit of Birkenhead

Quote from: sultanbev on 20 June 2022, 11:12:26 AMFWIW
these are the maximum (usually turret) armour values I've used successfully for over 30 years, the hulls are lower usually
M1A1 -               46cm Chobham
M1 -                 40cm Chobham
M1A1HA               51cm DU-Chobham
M1A2                    71cm DU-Chobham
Challenger 1         46cm chobham
Challenger 2        70cm Chobham
Chieftain Mk1-2      28cm
Cheiftain Mk3-10     39cm
Chieftain Stillbrew  49cm ceramic layer (turret only)
M48A1-A3             23cm
M60A1                26cm
M60A1 with ERA       31cm ERA
AMX-30B2             24cm (turret only)
AMX30                16cm
T-72M1               36cm ceramic layer         
T-72 monkey model    28cm             
T-72B                42cm ceramic layer         
T-62                 24cm
T-55                 20cm
T-64A                33cm ceramic layer
T-64B                37cm ceramic layer
Strv-103B S-Tank      38cm
M84 Yugoslav  32cm

Although the armour type is more important than the thickness in terms of being knocked out. Even if the figures are not quite correct, they will be a good relative guide.

Your sources please Mark. Also Stillbrew on a Cheiftain 9/12 is also on the Glasis, hence the front plate looking like a Challenger I.
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sultanbev

Too many sources to record going back 30-odd years, but includes Tanknet, a ton load of books, battle reports, pdfs and internet sites, and US wargames rules based on FM manuals. it's a synthesis of all the data out there that I've found, but not all the data that is out there I suspect, that's what we use and no one complains, and some of the numbers are similar to the Chadwick list you posted.

I've yet to see a picture of Stillbrew on a Chieftain hull, the only extra on the hull I've seen and built as Takom kits was just in front of the turret ring behind the drivers hatch, to protect the turret ring, and clearly none on the glascis.

HogansHeroes

Thanks for the responses all. I did a completely unscientific, but fun test game of a company of S-Tanks vs a company of T-62s. The S-Tank (with current stats) is really in trouble up against T-62, especially at medium and closer ranges. The T-62 has the same number of hits, a better save value of 4, and one extra shot (5 vs 4, although lower range). All for 20 less points! Even with the low profile ability, my poor S-Tanks stood no chance.

To be fair, I chose fairly dense terrain (real world map with plenty of urban). Maybe if I had kept it at longer range and used the extra 5 speed advantage it could have been better. I might have to do a few more tests (plus try out giving the S-Tank a 4 save and perhaps an extra hit).

Big Insect

22 June 2022, 10:56:52 AM #11 Last Edit: 22 June 2022, 02:22:34 PM by Big Insect
Quote from: HogansHeroes on 22 June 2022, 10:09:49 AMThanks for the responses all. I did a completely unscientific, but fun test game of a company of S-Tanks vs a company of T-62s. The S-Tank (with current stats) is really in trouble up against T-62, especially at medium and closer ranges. The T-62 has the same number of hits, a better save value of 4, and one extra shot (5 vs 4, although lower range). All for 20 less points! Even with the low profile ability, my poor S-Tanks stood no chance.

To be fair, I chose fairly dense terrain (real world map with plenty of urban). Maybe if I had kept it at longer range and used the extra 5 speed advantage it could have been better. I might have to do a few more tests (plus try out giving the S-Tank a 4 save and perhaps an extra hit).


Interesting test - thank you - as an observation, the point system is not an exact 'science' but more 'alchemy'  :D  The idea is to try and provide a balance across the game - as for example a lot of technology in 'western' armour is not necessarily reflected in the granularity of the rules (or are things that don't greatly effect the functioning of the vehicle in game terms - such as technically advanced driving sights etc).
But it's an interesting point about close terrain - as one of the advantages of the 'S' tank over the T62 should be gun range - especially at the longer range (e.g. over half range for the T62 but under half-range for the 'S' tank).

'S'tank - AP:3/125 | AT:4/125
T62 - AP:6/95 | AT:5/60

This gives the 'S'tank an ability to hit the T62s at between 125cm and 60cm (with AT) before the T62 can shoot back and then at under 62.5cms the 'S'tank gets an 'up-lift' of +1 d:6 for being under half-range.

The T62 player can shoot AP at 95cm and try and suppress the 'S'tank but it is going to be hard to hit as it will be attempting to hit on a 5 in the open and a 6 in cover. It also means that the T62's advance is going to be 'stalled' as the T62 must be stationary to shoot.

Generally, the longer ranges of Western tanks are designed to allow defense in depth, at distance, and good shooting 'lanes' in terrain are essential to give them the advantage over a usually more numerous attacker.

The close terrain in parts of Sweden will not favour the 'S' tanks mode of operation, but at higher latitudes and more open tundra, heath type terrain I suspect it would be very effective.

All just really food for thought ... when I get some time (between list writing  :) ) I'll dig out my own Swedes and playtest them - although I tend to play them as a matched pair against my Soviet Murmansk formations and they are using the T55AMs - which means the longer range of the Soviet ATGMs can play havoc with the 'S'tanks in the open terrain. So it's a balance.

Thanks
Mark

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This communication has been written by a dyslexic person. If you have any trouble with the meaning of any of the sentences or words, please do not be afraid to ask for clarification. Remember that dyslexics are often high-level conceptualisers who provide "out of the box" thinking.

Kiwidave

Coming into this thread with little knowledge of either tank in the OP, but isn't the S tank more of a tank-destroyer than an MBT? So more shoot-and-scoot than go toe-to-toe with the enemy?

Big Insect

22 June 2022, 12:32:32 PM #13 Last Edit: 22 June 2022, 12:38:19 PM by Big Insect
NB: if you were looking at published 'official' stats - ignoring tactical doctrine etc. - you'd probably be looking at the basic T62 being AP:6/100 | AT:4/100 by my reckoning, but that is by no means 'scientific' and doesn't help your 'S'tanks at all. 

There is an interesting argument that you could apply 'training' factors to armoured vehicles - a bit like we do with the Infantry (e.g. Conscript - Regular - Elite) and that that should have an effect on MBT gunnery - which I am sure it did in real life. I might consider that as a future optional rule - although it is likely to have an impact on the ability of certain units to hit the target more readily.

There are so many variable factors to take into account - if you look at reports from the Gulf War - there is the longest distance acknowledged official tank 'kill'- which is recorded as follows:

On 26 February 1991, a UK Challenger MBT achieved the longest range confirmed kill of the war, destroying an Iraqi tank with an armour-piercing fin-stabilized discarding-sabot (L26A1 APFSDS) round fired over a distance of 4100 m (just short of 3 miles) by callsign 11B, the CO of the Royal Scots Dragoon Guards tank. Impressive.

I don't know the full circumstances around this, but you'd have to guess that it was across a lot of very flat desert and in optimal temperature and weather, and with the Challenger stationary and able to lock onto the target, which must have thought it was well out of range, so was probably not taking any evasive action!
'He could have lived a risk-free, moneyed life, but he preferred to whittle away his fortune on warfare.' Xenophon, The Anabasis

This communication has been written by a dyslexic person. If you have any trouble with the meaning of any of the sentences or words, please do not be afraid to ask for clarification. Remember that dyslexics are often high-level conceptualisers who provide "out of the box" thinking.

Big Insect

Quote from: Kiwidave on 22 June 2022, 12:30:31 PMComing into this thread with little knowledge of either tank in the OP, but isn't the S tank more of a tank-destroyer than an MBT? So more shoot-and-scoot than go toe-to-toe with the enemy?

Maybe, but it is classified 'officially' by both Sweden and most other NATO countries (& Jane's) as an MBT - but I see your point. Maybe they should be operated more in that mode - fire and retire - maintain the optimal gun distance between them and the T62s.
'He could have lived a risk-free, moneyed life, but he preferred to whittle away his fortune on warfare.' Xenophon, The Anabasis

This communication has been written by a dyslexic person. If you have any trouble with the meaning of any of the sentences or words, please do not be afraid to ask for clarification. Remember that dyslexics are often high-level conceptualisers who provide "out of the box" thinking.