A random question - CET hatches

I am planning to model a 1/72-scale CET (Combat Engineer Tractor). This is a 3D-printed item, with both commander’s and driver’s hatches closed. To save me the trouble of opening-up the hatches, would it be feasible for the vehicle to operate (discharging soil onto a pipe fascine in an anti-tank ditch) with the crew using their periscopes, rather than with their hatches open?


I imagine Paul that if they were doing this under fire, then, provisionally, “Yes”; however, I’m sure some of the ex-Sappers here on the site will answer far more accurately very soon.

Good luck with the project - 'looking forward to seeing it in due course.

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Thanks for that.
As I mentioned, I am hesitant about attacking the cupolas with scalpel and mini-drill (mainly due to the size and 3D-printed resin). The idea is to incorporate the model in a BATUS-theme vignette … anti-tank ditch with pipe fascine in place, and CET discharging soil over the pipes. Of course, it would be sensible to have a clear unobstructed view during such an operation, but perhaps the crew has been specifically instructed to carry it out under ‘battle conditions’. Just a thought …


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Incidentally Paul, back in roughly 71/72, a full scale wooden mock-up of the CET was parked on Ripon Barracks square in Bielefeld, FRG. It occupied one corner of the square, shielded by trees, presumably to defeat Soviet satellites, surrounded by barbed wire, and with an armed guard from the Mixed Services Organization. It was tarped at night. It had been shipped over from the UK for the Corps Commander’s Study period, an annual event when all sorts of doctrinal stuff, the Soviet threat etc was all discussed for around 5 days or so; invitees were most of the BAOR hierarchy. I remember the CET attracted a lot of attention, not least due to its very unique contours and design.

Now there’s an option if you don’t want to drill out hatches: a couple of trees, an armed guard and just spray the thing gloss bronze green(!)


That’s not a random question at all.

This is a random question:

What is the allowable Position tolerance of the hole if it measures out at 22.50?



Now that is a random question … not sure that I understand it at all.



That certainly is an interesting diorama scenario.
It would save the problem of opening up the hatches.
However, I have just bought materials to scratch-build
the fascine, along with some ‘4mm dead grass’ for the
base groundwork.


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This is yet another really interesting armored vehicle I had never seen before today. The replacement vehicle with the scoop is also really neat.

As an Ex CET Commander myself I can answer your question.

All obstacle breaches were done closed down. Operationally (BATUS good example) without exception. The only time it was ever done opened up, was during baby steps training.

In addition, the CET could deploy Class 70 trackway from the bucket. It was tried (we tried at Bovington) to do same with a fascine. The idea was that a CET could approach the ditch, deploy the fascine and begin the breach straight away. It just didn’t work very well, the fascine was simply too large for the bucket and hydraulics also complained under the weight.

As it was, it was much slicker (and we were really tight believe me) to get the AVRE to drop the fascine, reverse out and then a CET prepped with a bucket of soil to come in and begin attacking the obstacle.

Just remember that in BATUS, all anti-tank obstacles were dug prior to the start of the Med Man season (usually done with civilian plant and sometimes 8230s T-Pushing) and were then repeatedly breached until the end of the season.

Therefore, construction of the ditches usually didn’t leave much grass about in the vicinity of the ditch anyway and it was rare for anything other than shoots of grass to grow in between Med Mans before it was tracked again.

Go easy on the grass. Sandy type soil is more accurate (at least in the vicinity of the breach).

Now there is a larger and potentially more interesting diorama,
AVRE backing out while turning to clear the approach and a CET approaching, turning towards the ditch
Should the CET come in straight instead, following the tracks of the AVRE?
A straight approach would get visually cramped. AVRE closer to the ditch and the CET on a straight approach but a little further back? Cramming things into a limited size diorama implies making some “adjustments” to the 1:1 scenario.

Many thanks to you all for your enlightened responses.
At least I can avoid having to open up the CET cupola hatches,
which would possibly damage the surrounding area of the model.


There was usually a minefield in front of the ditch, so the AVRE would plough up to the ditch, drop the fascine, and reverse out in its own safe lane. Then the CET would follow.

We kept WELL apart, at least 50 - 100m. Spatial awareness is hugely compromised when closed down. Usually, the CET would ‘talk’ the AVRE back out of the mission on Troop net, because they couldn’t see behind them at all.

A full bucket of soil was taken from anywhere available, but the most important thing was to arrive at the mission with a bucket full ready to go.

The CET can’t ‘doze’ in the true sense, so the technique was drop the first load on to the fascine. Then reverse up and begin filling the bucket in a shallow ramp as you approached the fascine, dropping what you had collected onto the fascine. If there wasn’t a minefield in front of the mission, this was easier as you could gather soil from further afield and make a sort of ‘funnel’ into the mission which the chunkies would subsequently defile mark.

When there was enough soil on the fascine, you levelled it as quickly and efficiently as possible before then attacking the bund. Making sure there was sufficient soil cover on the bund was essential because

  1. The damn fascine was only just a bit wider than the vehicle traversing it;
  2. The pipes are plastic and especially in the wet (when wasn’t it?) tank tracks and plastic fascine pipes had a tiny friction coefficient and you need traction when attacking the bund. I’ve seen more than one unclucky CET crew slide off the fascine into the ditch because they hit the bund too hard, were stopped and then the tracks would start to spin up. Eventually, over you went if you weren’t careful.

The technique here was to drag soil from the bund back down onto the fascine until enough of the bund had been removed that you could push through (remember my comment on traction previously) (this phase was something an AVRE would probably really struggle with, because generally, the base of the bund was above the level of the fascine).