Monarchist, I do appreciate the response.
The rough terrain unit will not work due to my overhead clearance issue. Im putting a 103 inch peg through a 105" hole... mast is too tall on the off roaders.
Hear yah. Different venue. VA DOT "may" be equivalent, because the Laws of Physics are. Our probable is called '21A'. IRC a 3" gradation right down to crusher dust, so it does compact well, and 24" - probably dictated by Canadian winters - sounds good, so long as it is A) WELL DRAINED, which 'saturated' puts the lie to, and was B) properly compacted in 'lifts' not overly optimisticly thick when placed.
The problem with not being well-drained, and all-year-every-year is that the soil under it goes straight to Hell in a mudpie, even if the soil itself would have had relatively high load-bearing and trafficability in its own right at lower moisture content.
Read on.
Base unfortunately is peat bog with a 1' base of pit run on top,. Its a never ending battle... and when the gravel fines get saturated, things get a bit spongy. When dry, there is zero movement. Its the lubricity the moisture adds that had me concerned, as it really cuts into locking forces of the fines.
Prehistoric peat-bogs are the bane of our existence, even a hundred feet down.
Basically, you are f****d and already know how and why.
If you cannot rent steel plates or wait for a month of drought, buy the plate, have holes burned for chains, place with the FL as you walk it to the load.
Raw steel of that sort isn't all that costly if you have a source that can deliver. We do, here. Also a recycler that sells used plates from major projects after their contractors wrap up and go off to the next job. Usually somewhat bent ones, but BFD.
So - not riggers - heavy construction sites, MAJOR road-builders who break down and sell-off at completion. Those in routine repair and maintenance keep an arsenal of their own plates stashed.
The question I'm really asking is, will the shear strength of the plywood hold up to the counter fluidity of the gravel base. Im no roads engineer.
Doubtful, but maybe. This ain't no 4,000 lb mini-FL nor load, and the worry as to Forklift TIP OVER to the side is far worse than getting frame-deep straight down..
I'd place timber grillage if I had no steel, but that eats way more of your overhead clearance.
Wacky idea... what if I dig a hole on the low side of the drive grade and use a pedestal style sump pump to try to drain excess moisture from the gravel. I understand that capillary action will keep the gravel damp for a LONG time, but if i can get enough water off to prevent saturation....??
Not 'wacky'. Undersized.
Google 'Stang wellpoint'. What Dad used 1953 to save a major power substation stupidly built on a peat bog, also what he game-planned fixing the Leaning Tower of Pisa 40 years before they finally DID it. FREEZING the soil at depth and upward to create a wall is also involved.
It is the PEAT below it you have to drain, and it is a non-trivial exercise, especially if there is a subsurface source of more water that extends beyond your small patch.. as it will do.
Your area almost certainly publishes DETAILED soils geology online - I have used Canadian sources for that before.
If you could afford to cut-off water ingress, actually drain the peat, it would then compress, stabilize, soil and gravel above drop a fraction. This needs more time than you have.
The big bucks are in diverting water ingress and draining stuff over a wide area under structures you do not control, so "faggedaboudit" as to permits. You cannot afford the liability cover if even you could afford the planning, etc.
Get thee steel...
OR .. .pay attention, there may be a quiz later....
.. do a safer-site-nearby / terminal
transfer to a
rollback so you have the overhead clearance back in your favour.
No forklift == no mast.
Then you can timber a 'roadway' for the roll-back's wheels, add THIN steel plate for where the equipment comes off the rollback and onto rigger's skates for the last-leg.
Hands down, now... I'd do it that way.