Gday all
This is my initial plan for a new diorama in mind...


Excuse the knock-about drawings, but what you can see here is M4A1(76) halted on a somewhat muddy road in Belgium(?) because of road damage done by artillery... There is a slope on the left down to the road which will either have a copse of trees or some pines from the edge of a plantation... there is a fence line with posts (The straight line with 'dot' posts) On the opposite side the slope continues (as the road in the beginning would have been cut in to a consistent slope)
The crater in front of the tank will be 1/4 filled with muddy water, and there will be remnants of the blast as in dirt sods scattered around etc... 2 crew are standing at the front edge of the tank, basically pondering how to navigate the roadblock... The gap on the left is definitely too tight with the fenceline and tree in the way, and the other side has a partially leaning telephone pole, on which I may have another crewman giving it a shove with one hand to see the how easily it could be knocked down to give passage to the tank...
Does this show any premise? The crew figs. I have are rugged up, so there will be winter grasses on either side...
Thanks for any feedback~
Cheers
Brad
Oh, and the size of the crater has to be sufficient to prevent the passing of the tank on a road of this width. What artillery would make this sized crater? 88 perhaps?

Good drawing - good planning.
One Arty shot - hmm - take out a few trees with pot holes and it would improve the scene.
Maybe have a sapper filling in holes too.

Definitely a good idea, I know you could do a good job on it. Let the ideas flow for a day or so....

I like it. At first your drawing looked like a classic linear ambush. As for the crater, even a French acquired 155 would be hard pressed to create that hole, but there certainly was ordnance available (including US bombs) that could. Since I know from another post that Thataway3 has a copy of FM 6-50, (I had to turn mine in when I left the unit) you might ask him to scan the section on crater analysis to get a good idea what shape the crater will actually be.

Very nicely composed & compact scene Brad. Got a bit of topography to boot too. For me the tricky bit will be which side will be the frontal view. Having the left side of the drawing as the frontal may obscure the tank given the pines and slope. It will leave either the bottom of the picture as the frontal or the right side. I'm partial to the right although it would be nice to look into the muzzle of the barrel. Just my thoughts.

Maybe a scond crater among the trees knocking one down onto the road making another obstacle to cross

If you want a crater to stop an M4, you'll need a crater about this big:

Sorry about the picture of a picture, but in '83 we didn't have digital cameras.
This was made from 50 pounds of C4 fashioned into a cratering charge during SF Demo training.

The 155mm shell weighs in between 95 and 98 pounds, and only has 15.8% explosive (comp B) by weight.
The 8 inch weighs 200 pounds with 18.5 % explosive by weight. Soooo...
With some rough math here, it looks as if it would take a German 21 cm Mrs 18 with a 250 pound shell to do the job for you. Definitely plausible, although there's no conceivable way to convey in your dio (which looks very cool on paper) it's still fun to know.

Thanks for the quick feedback lads...
CK, I was leaning towards the front focal point being the bottom of the pic, where the crew can be looking to the figure's progress with the telephone pole?
And Alan & Scott, I like the ideas of a second crater, and knocking a tree or two down... What about a couple of smaller craters on the road itself, with both causing the collective problem of one larger?
18Bravo, thanks for your research! Your conclusions lend themselves to me choosing smaller craters... I think...
How about:
A couple of toppled poplars, maybe crushing the fenceline in a place or two, (Maybe one leaning on another, and one completely felled?) but not having one in front of the tank as the foliage may obscure what I want to do with the figures and also the tank itself...
A crater inside the fenceline, and a couple in front of the Sherman?
Hmmm....

What about if it was a small bridge that fell in? On small rural roads, especially on hill sides, small streams frequently run down the hill-side and have simple stone bridges built over them. If this got hit or was exposed to heavy vehicles it could also explain the hole obstacle. Just a thought

STOP it with the good ideas!! :-) That said, I'd be opening a Pandoras' bx of modelling misery if you think I should model a stream flowing rapidly down the slope hehe...
Have desided to do some more practise on an older dio and see how some techniques knit together... Hope to post some pics tonight