Harecastle—simple solutions without going daft, suggests Paul Burke.
Count them in
(1) Count them in and count them out. Whenever a boat enters, the staff phone the description, name and registration to the far end. If not out in the given time, all entry is suspended and a search boat (with loud-hailer, water-level search beam, blue flashing light and caged prop—we don't want to mince the poor guy in the water) is sent in slowly from the end last entered (how deep is the water there?).
Pinch wires
(2) Put in a leaky feeder GSM repeater. I'm not sure of the legality of these overground, but there should be no problem in a tunnel, and it gives the crew of a stranded boat the chance to dial 999. Don't buy it from Capita at £100 million pounds, get the local radio club to design it:) If you can't do that, put in a pinch wire like the London Underground has. Two bare low voltage wires, if anything is wrong you grasp them together and set off an alarm.
Bump caps
(3) Bump caps are better than hard hats—they are more comfortable, give reasonable protection and don't add so much to head height—important as an ordinary site hat could add to that problem. Make head protection and high- visibility jacket for the steerer a mandatory requirement for entry. Trad stern boats are possibly the biggest problem, as you can easily step back and fall off if disorientated in the dark or if bashed on the head.
Guide lights
(4) Guide lights through the tunnel—it can be hard to see the daylight when going North, and the door is shut going South. LED rope costs about £60 for 20 metres retail. For a rope each side, 2600 metres that's £16,000 at retail prices.
It takes 3W of power for 20 metres, that's about 800W for the whole tunnel. For comparison, prior to converting to LED the halogen lights in my kitchen were using half of that. No doubt health and safety and profit margins can push up the cost to a hundred thousand or so.
Don't panic
(5) Don't panic. Not many boaters get killed going through Harecastle or any other tunnel. Some boats get scraped paintwork around the cabin corners, and that's not quite up to the end of the world in seriousness. As someone else said, be sensible and don't crawl through as it's harder to steer a slow boat. Don't stand within the arc of the tiller, keep your head down if you're tall, keep the passengers under control. And enjoy the dark mystery of it all. I've never seen Kit Crewbucket yet.
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