So there I was, trying to lift my gates onto the hinge pins...and I couldn't do it.
It wasn't just the sheer weight of the gates that was the problem. Now that they were assembled into their bi-fold form the outer section of the gate would flap around uncontrollably, and the fact that I was trying to do the lift on sloping ground didn't help, either. I could get the gates into the position in this photo - propped up just an inch or so away from the hinge pins - but the final manoeuvre, up and over the hinge pins, just wasn't going to happen. My puny human strength just wasn't enough.
I realised I would need some sort of crane. Like an engine crane. So I bought one.
I'm sure it'll come in useful. I might even lift some engines with it one day. But for now, it works very well as a gate crane. The only problem was the sloping ground. Engine cranes don't come with brakes, and the whole thing was in constant risk of rolling down the slope, gate and all. But the actual lifting operation went very easily. I should've thought of doing it this way in the first place!
My camera decided to go a bit wrong at this point, so unfortunately the only photo I've got of the lifting operation is this one, which is fairly terrible. But it shows the crane in action well enough. I could get the gate right over the hinge pins with no trouble at all, then it was just a case of letting the jib down a bit, and it all came together with a satisfying clunk
This particular crane is marketed under the Switzer name, but like my Von Haus concrete breaker it's really a generic product made in China. It seems to me that I could set myself up as a tool brand, buy everything in from China, stick on my own brand (something European-sounding, like TECHNIK TOOLS), and make a fortune. That seems to be what everyone else does these days.
I did wonder how much it would cost to make an engine crane in the UK. After all, it's mostly just box-section steel. Any metal fabricator could do it. But I suspect you wouldn't get much change out of a thousand pounds. I bet the factory gate price in China is more like twenty quid.
It seems that the gate sits just off the base of the bottom hinge pin. I suppose I could shim the pin up a bit to fill the gap, but I don't think it matters. The weight is taken by the top hinge - the bottom hinge pin just locates the gate, rather than supports it. It may well settle a bit in time, anyway.
The clamp around the gate end post looks a little loose in this photo because I haven't give it a final tighten yet. It's possible to adjust the gates to a certain extent by moving this hinge in and out, but that's something to do only when both gates are on and basically lined up. Then you do the fine adjustment...
I know what you're going to say. I should have put the bottom hinge pin upside down, to prevent the gates being lifted off. Well, I decided not to do that - mainly because it would have made it more awkward to put the gates on
in the first place.
But I don't think there's much chance of anyone lifting the gates off. When both gates are locked together you'd have to lift what is effectively a a 6-metre long gate which weighs something like 250 kg in total, and would move like a giant snake as soon as it's lifted off its fixing points. It would take a team effort by the All-Wales Olympic weightlifting squad to lift it while keeping it under some sort of control. Frankly, if anyone wanted to break in through the gates, it would be easier to unscrew the hinge pins and push the whole lot off the posts.
There are various devices which fit over hinge pins to stop gates being lifted up - collars which fit on to the pin with a grub screw, or which can be padlocked on - so there are options available if I decide to install a bit of extra security. But I think the sheer size of the gates is the best deterrent to anyone who fancies having a tamper.
So, after a certain amount of lifting and shifting, both gates were on. In this photo I have temporarily strapped them together with cable ties, and propped them in place with concrete blocks. I prudently parked my Land Rover outside the gate before I locked myself in...
The next stage is to install the hardware. The first thing I put on is this throw-over - a device that does exactly what it says on the tin. It straps the two gates together. This version can be padlocked down. Theoretically you could get around the padlock by undoing the bolt at the other end, but I think it would be quite difficult to knock the bolt out. It can't be pushed out by finger pressure.
Then I strapped long pieces of wood to the gates with cable ties, to keep the whole assembly straight while the drop bolts went on. The concrete blocks help to keep it all steady, too.
I had to buy extra-long drop bolts, to accommodate the sloping ground, which of course slopes away from the gates and means the bolts have to drop a greater distance. All the hardware is going on the inside of the gates, and I made sure that gates are all positioned so that the coach bolts which hold the gates themselves together have the smooth end outside, and the nuts inside.
Then it's time to get out the heavy-duty drill bit...
...and drill holes in the ground for the drop bolts to go into. I made sure to go through the Tarmac into the underlying concrete.
Slightly to my relief - because I did it all by eye, without measuring anything - the holes were in the right places, exactly under the drop bolts. This is the middle bolt, which can be padlocked down. I'm only installing 3 drop bolts. The gate section to the right doesn't have a bolt: it's fixed in place when closed by the throw-over, which locks it to the gate on the left, so theoretically it won't need a drop bolt of its own. However, if it seems a little wobbly I can always install a 4th bolt.
I could probably get away with just the plain drilled hole, but the kit of parts includes these little collars which fit into the top of the holes and keep everything neat. They're what is known in mechanical engineering circles as an interference fit, and in civil engineering circles as a bash-it-with-a-hammer fit.
There's also a little square top plate for the finishing touch. I think these are really intended for use on smooth concrete floors, rather than rough Tarmac, but I decided to fit them anyway.
And that's how it looks, when it's all fully installed. This is one of the inner, non-lockable drop bolts, although I could make them all lockable if I wanted, by adding the padlock holder. The trouble is, of course, if everything
has a padlock on it, that'll make the business of opening and closing the gates such a faff that inevitably some of the locks will end up not being used.
By the way, it was raining on and off on the day I did all this, and you can see how dark the timber has become because it has absorbed so much water. The bottom parts of the gates were noticeably wetter than the top parts, which suggests the water was oozing down through the wood. I have no idea what sort of wood the gates are made of, but they certainly seem to absorb more water than the fences. They dry out quickly enough once the sun comes out, but I think an extra coat of preservative might not be a bad idea.
One little refinement I added were these straps to keep the two sections of each gate together when they are opened. After doing a few test open-and-close moves I realised that the gates were rather awkward to handle if the two sections were free to move independently of each other. These straps mean they move as one.
Here's how the left-hand gate looks, when it's folded in half, strapped together, and fully opened. You can see how little space there is between the entrance and the building - a full-length gate would definitely have got in the way.
I put in a couple of posts so that the gates can be hooked back in the fully-open position. The installation of this post got a little messy, because I was using Post-Fix (a kind of just-add-water instant concrete) and I lost control of my bucket of water at the crucial moment. But it'll all be tidied up and landscaped eventually.
There's no hook on the post yet because the local hardware store only had hooks in brass or black finish, and that would never do. It's got to be galvanised or stainless steel, to fit in with the silver/grey colour scheme!
And that's pretty much job done, apart from a few finishing touches. The gates are on, and work really well. The great thing about the bi-fold design is that they're so flexible - there are several different ways of opening some, or all, of the gates. By opening just this section the gate functions as a neat pedestrian entrance.
Having gates across that wide Tarmac entrance does create a definite sense of privacy and security. Even though it's possible to see over (and through) the gates, even though it would be possible for anyone to climb over them, the psychological impact of having an actual barrier across the boundary does have a real effect.
This is what passers-by on the road see. A very traditional sight, in a way - you would hardly guess the gates are brand new. They look like they've always been there. And it does visually tidy up the front of the building quite a lot. I particularly like the way it's not possible to see how the gates work at first glance. Because all the hardware is on the inside, it's not obvious that they're bi-fold gates.
The gap between the gates came out at 5cm, which was a little wider than I was aiming for - I wanted to make it 3cm or so - but I'm not going to quibble about a couple of centimetres. One of the finishing touches I plan to do is to add two strips of wood to the inner faces of the end rails, which will fill the gap and make the gates fit together like double doors.
I think I'll file the job under 'Not bad if I say so myself'.
In some of the photos you can see I've built a hoarding across the front of part of the building. Nothing fancy, it's really just to screen off what will become a building site fairly soon. Some photos of that under construction will follow next time...