Tank Trench.

The idea of "tank trenches" is actually still in use to some extent. They're not so much actual trenches as just a series of dugouts along the line and most of the time they're not for actual tanks but more for infantry-carrying APCs with heavy machine guns and 20-30mm cannons.

The idea is that as you dig your line for the soldiers, you also dig huge holes for the APCs to drive into along the line, leaving just the top cover weapon exposed. When the enemy hits your line, not only do you have your heavier weaponry in the fight from the beginning with a lower risk of having your vehicle taken out by enemy AT weaponry, you also have the option of loading the entire unit into their vehicles to either change positions, advance or retreat fairly quickly, depending on the situation.

An infantry company with 3 platoons can usually cover a line of around 300-600 yards depending on the terrain and have a secondary position for each platoon that extends the AOR 100-300 yards tops. With the APCs with their heavy weaponry in place, you can easily throw in another 100-200 yards on your basic line (vehicles on the flanks have greater range and vehicles along the lines can cover a larger area than small arms) and at least double the extention of your AOR with secondary positions, because you can get to them much faster.

The alternative is to park and camouflage the vehicles behind the line and either make do without your heavy weaponry and just rely on your small arms, or unmount the heavy weaponry from the vehicles, in which case changing positions and getting back to the vehicles in general is suddenly a more time consuming task. With both of these options you're usually also two men short on the line for each squad, since the drivers and vehicle commanders/navigators have to stay with the vehicles, both to protect them in case the line is broken and to constantly be ready to move the squads if needed.

There are advantages and disadvantages to all of these solutions, which is why the "tank trench" way of fighting is still taught to Danish mechanized infantry, even though most of what they're being used for these days is counter-insurgency, which doesn't require a fixed line.

I know Danish tank crews are also taught something along the same lines, but it's not something they employ for longer periods at a time. The idea here is just to be able to hold the line until field artillery can take over. Permanently entrenching a tank for extended periods of time is poor use of hardware and manpower, but if we're only talking for a couple of days, it can be worth the effort. After all, a tank hiding behind a 20-30 foot bern of tightly packed soil is at least a little better protected against direct fire than one that's sitting out in the open.

It would be a variation of the Hull-Down tactic used by tanks. Basically the heaviest armor on tanks is that at the front of the turret, so you try to position yourself so only the turret is showing and the hull is hidden and protected behind something else. Apart from anything else this prevents a tank from being immobilized by a shot hitting the track.

This technique is normally done by driving up a hill and stopping with just the turret showing. But 'artificial' hills would work just as well...providing that your opponent doesn't have artillery and know where the 'hill' is located. Or aircraft that can drop bombs on you.

Soil is actually rather good at absorbing kinetic and explosive energy, and a sloping dirt 'wall' is even better. So even if you are being shot at by something that can get through the 'wall' its not going to have a great deal of energy left to trouble the armor of the tank.

The dig-a-hole-with-a-tank-in-it thing is well known, what I was trying to find was the sideways interconnected long trench where tanks can trundle for a distance with just the turret above ground height... ?..

How common was that ?.

Suggested....

The tank is left sideways on to the action, engine running if there is action, if it starts attracting a LOT of local fire, or even if the mortars get a range on it, it can bug out sideways to get a different firing position.

Not burying a who,e Tank but mounting the turret in a defensive bunker, is what I am thinking of.
Like the images on this forum.

forum.axishistory.com/viewtopic.php?f=70&t=14464

That makes some sense....

The Germans used demounted turrets including some Panther aus D and French ones along the Atlantic Wall.

good question - either you have a gas engine to power whatever normal power system they run on, or you put in electric motors to run on line power.

the same would be true of a fixed mount turret whether it was a repurposed tank turret or not.

In World War 2 only the Germans had powered turrets (the system was electrical I think). Allied tanks, until near the very end of the war, had manual cranks to move the turret. (I'd guess that the Germans had manual systems in case the primary system stopped working)

The manual system was probably something that came 'free' with a turret than was being used in a fixed position, and an electrical system was probably less useful as the need to rapidly turn the turret was not as important as it would be on a tank. (In the case of German emplacements fuel shortages would probably have made the electrical system, and the generator it would need, less practical anyway.)