Are these gantries on simple pole masts?
That looks a little.... odd.
Is this equipment going to be similar to the stuff the HOOP train is going to put out on the Great Western?
No and no...
There are a wide variety of OHLE structures going up.
The easy sections are simple poles as you say, but there is a sizeable proportion of portal structures (including virtually the whole stretch over the moss and east of the M60).
There are also plenty of L-shaped lattice structures like some in the pictures, where the masts are on one side but carry two lines of OLE.
I forget which is which, but there are two new NR OHLE standards, Series 1 and Series 2.
One for good to 100mph (which this is), and the other for 100-140mph (which is the GW spec).
Whether the HOOP equipment can do the lower speed routes I don't know.
I would guess the higher speed type will also go on the MML, but the lower speed will suffice for everywhere else.
Foundations on the L&M are a mix of concrete and tubular piles, but I think the GW bases are to be all piled (at least on the HOOP sections).
I shouldn't think the HOOP trains will be used in the complex layouts around Bristol and Cardiff.