Really compacted soil, best way to treat it?

Wowww...  You have a lot of gullible friends, WR.

Thanks for all the advice. I plan to do a bit of digging after work a couple of evenings this week.

After bending my fork in half dealing with something similar but was shiny and polished and the fork would not go in without extreme work - I now attack with a pick axe and then dig with a fork and get out as many weeds and root systems as possible - a whole year of digging and I'm only just 3/4 done.

I am getting very good with a pick axe though 

I've taken time to create paths and beds, and by breaking it up in that way you feel like you are making progress. Also take lots of photographs (I do each time the next bed gets dug), add them to a diary - that helps when you feel like you have hit the wall (as runners would say).

I would go for as much compost and manure as you can get, put it on to a depth of around 3-4 inches. That will stop it drying out much more and nature will start mixing it up. Then when moist enough then do a light digging to get it mixed a little better on the top. Nothing will happen immediatly without a huge amount of work.

Keep adding material over the next few years and dig it more each time, eventually it will be fine.

I would also mark out an area at a time as this can be done in any convenient size and you see results for that quicker, could also plant something in the completed section, and don't kill yourself trying to all in one go.

If you can get hold of heavy duty weed supressing membrane (expensive but lasts a lot better than the flimsy stuff) you can cover the dried out pan of soil while you work on another area. The membrane will allow rain in, reduce evaporation and stop it turning to mud, as well as gradually softening the ground. Additional benefit is it keeps the weed seeds off so it will be ready to go in the spring. Clay soil which yours looks like is generally quite fertile so you might get away with one or 2 seasons of not adding too much to the soil. Having said that Growmore or chicken manure pellets are a fair substitute for nutrients but not humus.

Work on another area you CAN get your fork into, turn it as best you can then cover with as much manure as you can get hold of. (Do you know of anyone with a trailer that can help you get some or do you know any farmer types who may deliver for a small fee?)

Once you have a workable area go back to the membrane covered area and turn it back little by little digging as you go. Personally I would then recover until I actually planted it up.

It could take you more than one growing season to get it fully workable, unless you have loads of volunteers to help you

if you want to plant the soil up now, you could do it the hard way with a folk or hire a rotavator which can still be hard work.

you could wait for some rain rake the ground well and sow some green manure - winter field beans are good for breaking up heavy soil and can be sown now into november.

you could buy in a load of manure, spread on the ground and leave the bugs to do the work.

I have a patch under plastic about 6ft by 9 which looks like yours underneath, Im hoping to use a bulb planter and pop some kale seedlings into the ground