Field gates

[Palustris]

We would like to replace our gates into the garden. The gap is 16 feet, at present there is a rusty old metal and a rickety wooden one covering the gap. We could fence but then we might lose the right of access. So, we were looking at decent wooden gates (2 x 7 foot plus 9 to 12 inch posts) Anyone ever had anything like this put up and any idea of costs? I could do it myself, but really do not fance the hole digging for the posts in rather stony ground and the weight of the gates may be a trouble.
TIA

[Palustris]

[ACE]

We had a fencing firm at a job I was on once, I watched and asked questions for future reference. The main thing that stuck was the post fixing for large gates.

The post hole should be big enough to hold more than the weight of the gate in concrete, also the post should be at least a third of its length in the ground. A good tip I noticed was that they put a poly bag on the end of the post with some creosote in it and buried the lot in concrete. They let the posts set for a week before they hung the gates.

[Robert_Brenchley]

Whatever you do, ensure that the post is solid. There's a lot of leverage on it from the weight of the gate.

[Palustris]

Thanks folks, but I do know HOW to do it, I just do not WANT to do it myself. I do nor want to be ripped off by a 'tradesman' so an indication of possible cost is what I want more than anything else

[Hex]

Without examining and determining the structural components of posts to cover the span, you could look at someone manufacturing a demountable fence for infrequent access. This could be made to "look like" a standard gate opening but be a semi permanent fixture. 6" by 1" gravel board at £5 a go could deliver this. (Got some spare here. And have the means to transport)
Otherwise, the cheat these days is to, concrete in an I section RSJ ( rolled steel joist ( 1.5x the gate height and say 9" width)) and clad the joist in wood or brick. The joist will take the structural requirent and the external finish will be for show.
Or pick the gates you require from Cannock gates et al or from BnQ  @ £400 (3.89m W) incl two posts (less discount for OAP when buying off peak times ;)) 
Combine your purchase with arrival of dutiful and hungry son-in-law and entourage;QED  :D

[euronerd]

Palustris, how about a farm sale for cheap gates? And I've seen this done before: a wheel mounted on the closing end, i.e. the opposite end to the hinges. Would save you having to dig a huge great hole, though you'd still need concrete I suspect, just not as much. Can't quote figures though, sorry.

Geoff.