Supply establishments?

[Lieste]

I've been fiddling with the SM, and have thrown together a few simple 'test' scenarios.

One thing that srikes me is the extremely large supply capabilities of (especially) the German forces - (In fact I expect this applies to the Western Allies as well, but have less material at hand to check the correct force sizes/supply strength).

It isn't so much that the strength in men/trucks is too high, but those actively responsible for supply distribution and movement only form a relatively lean force:

From the western desert a PzD has only 12 supply columns and a supply 'company'. This comprises:
a single POL column (size unspecified, but I assume equivalent to a heavy column?)
4 heavy columns, each 60 tonnes payload
7 light columns, each 30 tonnes payload
200-230 men in a work company for unloading/transferring cargo.
Total payload, for ammunition and basics supply, 450 tonnes.

Regimental supply is at most a single light column, and the integral capacity of the trucks held at company/battalion echelons - something on the order of 40 tonnes?

By comparison, the full supply capacity of the COTA units is:
Div Base - 828 tons (stocks 1023 tons)
Pz Regt Base - 162 tons (stocks 87 tons)
Schtz Regt Base - 166 tons (stocks 82 tons)

This is 230% of what looks to be a 'correct' level of supply.

I have experimented within the test scenarios with the supply echelon at 44% for Divisional supply (mot), and 30% for Regimental supply (mix of (mot) and straight infantry division regimental supply columns), and apart from the smaller unit footprints and staggering of supply arrivals over a longer period (each Regt column must make more than one trip if there has been rapid movement or heavy combat to service all companies) there seems to be little real difference so long as contact with Army/Offmap supply is retained.

I see a requirement for the Regt Base to be within the vicinity of the Regt combat arms to allow rapid replenishment, whereas the AI leaves Regt bases in the far rear, and pushes the Div Base forwards?

Having less than 50% of the ability to store and move supplies does discourage constant use of all the artillery on hand though, as this requires the entire supply lift to sustain

Need to still look at Allied supply, but my gut feeling is there is just too much here also - possibly the vast bulk of the rear echelon should be non-supply troops (signals, cooks, band, chaplain, graves, hospital etc).
It would be useful if the supply echelon could be made appropriately sized, but to acquire the ability to replace losses sustained from other non-combat arms, perhaps with a loss of efficiency if the replacements exceed a reasonable proportion of strength?

[simovitch]

Here's from my notes:

Bases PersQty, Capacity and Handling
Aim to clear the full backlog of resupply requests in 2 hours of loading. Work on 80% of trucks doing resupply runs – the rest are used for internal depot/base functions. As a rough rule of thumb a normal unit can employ 10% of its persQty for loading/unloading ( ie handling ). A Base/depot can employ 20%. Each man available has a loading capacity of 20 kilos. So if a Base has say 500 men, then 100 of these can be available for handling, giving it a capacity of 2000 kilos or 2 tonnes per minute. If a supply run has five 3 ton trucks, then the Base could load in 8 minutes.
So if you have 1000 tonnes of trucking total, truck capacity = 1000* 0.8 = 800 tonnes. The handling capacity required to despatch that over two hours = 800 / 120 = 7 tonnes. The number of personnel to provide that = 7000 / 20 = 350. Which means you would need around 1750 personnel assigned to the base. 
Base Pers Qty/ capacity guideline:
Army/Corps = 1000 pers, 500 tn trucks
Div = 600 pers, 150-300 tn trucks
Bde = 400 pers, 100-200 tn trucks
Regt = 250 pers, 50-100 tn trucks

I think supplies in COTA are way too abundant, but on the other hand there are limitations on getting the supplies delivered, especially with the man-packs of the airborne.

In BFTB the scenario designer has the ability to set initial stocks of bases and for units. You will find that in most scenarios the Germans of 1944 are living a very thin line compared to 1941.

[Lieste]

Using a fairly detailed Orbat for Greece '41, and the example of 11PzD:

There are light supply columns (mot) with:

1/PzRegt33 (plus Pz Maint column)
2/PzRegt33 (plus Pz Maint column)
SchutzRegt110
SchutzRegt111
231AufklBn
85 SignalsBn
86 PnrBn

Note that two of these are regimental supply columns, but five support a Bn directly.

The division supply troops:
61 Mot Supply Troop (comprising):
1st-7th/61 light supply columns
8th-10th/61 heavy POL columns
1st-3rd/61 maintenance columns
61st supply company (according to allied intelligence report this was ~300 men in (IIRC) 21PzD in the Western Desert)

Total supply quantity reported is only 600 tons, of which less than 400 is at Divisional level.

In addition there are rations units - Butcher/Baker and the Divisional Admin troops and medical/ambulance troops. However none of these are distributing the supply forwards.

As previously noted the Dep tab in COTA indicates the Divisional supply capacity (for deliveries) to be at least 828 tons.
Add in the 162 for the Pz Regt (~60 by OOB) and 166 each for the SchutzRegts (~30 each) and the total Divisional lift capacity is 1156 tons - or roughly 200% - this makes incremental losses almost irrelevant until the point that the base risks evaporation.

The 'total handling' may also be too high - if 20% of the persQ is active, then 190 men are active at Div Base, 200 at Pz Regt Base and 300 at SchutzRegt 110 and 111. This is over 200% of the 300 reported strength of the supply company - even accounting for drivers, the depot side seems too high.

[Arjuna]

Lieste,

You may well be right about their capacity being too high. Keep in mind that while we aim for realism, we also must balance that against playability and bear in mind the limited resources we have to develop things to perfection. By all means feel free to save an existing scenario under another name, modify it and test it to see if you can a better fit that is playable. If after testing you think you have a more accurate and playable version, then post it up at one of the fan sites for others to download.

[Lieste]

What troops are considered part of the 'Base'?

I haven't found anything terrible useful for ww2 Allied stuff, but I do have a detailed Orbat for 4CMBG c1958.

Here the Supply company has 4 platoons with a total of just under 100 vehicles and a ~300 tonne capacity (WAG, but consistent with the nominal total for LOC troops below).

The rear echelon troops, including commissary, signals, supply, maintenance, ambulance and medical companies have ~300 vehicles with a ~750 ton capacity (plus recovery and tank transporters). Some of the trucks should be non-payload carrying - workshop bodies/signals vans etc, but for a first cut they have all been counted as basic lorries of their equivalent size. Trailers have been counted towards the payload totals where present, but the increment might be lowish.

So roughly 1/3 of vehicles and 40% of the rear-services payload capacity are available for the 1958 CMBG supply operation.

If this 40% capacity and 10% handling were applied to the COTA estabs, then the supply load, the supply capacity and supply rates would probably reflect the occasionally tenous supply situation rather closer than the current 80% and 20%. Currently there seems to be little to stop the player setting everyone on fast rate of fire and high mobility - the four supply runs per unit per day can be easily dealt with. With half the rates, the supply should be adequate for normal rates of advance and normal rates of fire, with the option to dip into stocks if supplies are slow arriving.

With the regimental supply columns forward with their units (which isn't happening with the AI control) a two hour turn-around gives ample time to make 4 supply runs with ease...  With half the handling and carrying capacity each lift still only takes 2 hours to prepare, but multiple runs per column for the shipping of supplies might be required in total commitment/high use periods - this should still allow 3 or 4 runs per day to each supplied unit...


The positioning of supply echelons is dubious sometimes. In a custom scenario and with 2AD moving NW up the Thermopylae map under AI control I repeatedly find 2AD base just behind the railway tunnel and 1ABde, 3ABde, ?IBde Bases south or east of the wooded central area on the valley floor. It seems more likely that 2AD would set-up in the far south, and 1ABde, 3Abde and the IBde Bases would provide intimate support to their assigned battalions only one or two 'bounds' to the rear and just out of direct fire range (preferably in dead ground, but this may not always be possible - in which case they may be a bit further back out of normal indirect fire range). The AI also displaces my own Regt Bases far to the rear if they are re-subordinated, while it leaves the PzD Base closer to the front when it is re-attached to the Div HQ. This will certainly have an effect on supply turn-around rates and delivery lag.

[Arjuna]

There are only two standard ressupply runs per day and only one if the scenario designer sets the side to only receive supplies at night. In COTA there are unlimited emergency resupply runs allowed for, subject to available supplies, transport and priorities.

[Lieste]

1) The 80% doesn't seem to be a fixed limit - I had a cut down Divisional Supply Troop, with a nominal 330 tons supply capacity. At one point in the battle I observed the current payload to be 355/330 tons (107% of nominal). (However, I note the overall payload of the unit is much higher, including internal reserves - the payload limit nominal is 71% of the total lift, and the observed value is 76%)

2) Are there any really important reasons not to attempt using 2 bases at a given level? I have experimented with a supply and rear echelon unit in two separate bases - this gives the poor quality rear services troops in the correct proportion, with a reasonable supply limitation - the supply troop is the first at each level, with other base admin troops in the second unit. The behaviour appears to be that only in direst straights will the second unit begin to ship supplies (and presumably it would take over the supply role if the primary unit was lost?).

3) I've also experimented with replacing the Recon Bn HQ with a cut-down Regt HQ so it can receive it's own Recon Light Supply Column, but this causes a few minor problems - the incorrect size designation, and the supply troop not moving in direct support of it's Bn (who's role often leaves it deep or wide).



(re, no 2) )
A possible issue with using two supply elements on more than one level - I got a CTD at the end of the 06:00 impulse on D2, when I had both Divisional Supply and Divisional Rear Svcs Bases (40/60% Str) and Regimental Supply Columns and Regimental Rear Svcs Bases. Removing the Regimental Rear Svcs Bases, and only having duplicate Supply elements at Divisional Level and the scenario proceeded normally, with no supply routed through the Divisional Rear Svcs Base as intended.

Whether this still works with a Corps Level Formation and multiple Divisions is something I want to test in a new mission - I assume that I could still feed supplies to Division Supply/Rear Svcs if the Regiment and Corps Level are single elements.

There seemed to be no real issue with supply quantity or timings for the division in moderate combat over a 48 hour period - the Division Supply Troop was picking up supplies from an Army level forward dump (Airlanded Supply Source on a Road) and passing them forward to 16 supplied units (including 4 Regimental Bases and the Divisional Rear Svcs Base). The Regimental Columns were passing supply forwards as required with around 3 hours turn-around for all supplied units even in heavy contact - aided by manually pushing the supply columns forward into the rear of the combat area, Division had kept up with demand and all bases had nearly full stocks except immediately after pushing routine supply forwards.