Harecastle Tunnel - inexperience

[GreyLady]

I've been reading every post and thanks for everyone's reply's/advice. If we end up doing the harecastle I will post a video.

 

Good stuff thanks everyone.

[Ray T]

How Blisworth Tunnel was built:

 

[Guest]

How Blisworth Tunnel was built:

 

https://www.youtube.com/watch?v=sYHBt0shQY0

What, no laser guided tunnel boring machine?

[captain birdseye]

May have been the way in the past, but not nowadays.

There is certainly no length definition in the Rule Books.

I remember it was something that was asked when I was at Signalling School and no definitive answer could be found.

It's in or was in GC/RC 5603

 

It takes an S&T man to read standards

[RLWP]

What, no laser guided tunnel boring machine?

 

Well, if the theodolites use light - like a lasers, and the team of tunnel borers were as organised as a machine, it's much the same

 

Except the TBMs work from one end where the manual teams had several faces being worked at the same time

 

Richard

[Wanderer Vagabond]

 

According to a quick calculation, if it takes two minutes to get a full length boat through (from the stem entering the tunnel to the arsend emerging) the transit speed is about 0.36m/s or 1.2ft/sec, or if you like, 0.8mph.

 

You could leg the boat through at that speed.

Similar quick calculation, if my boat is 18m long (not a full length boat) and the tunnel is 21m then I'm going to cover 57m between the pointy end entering and the roundy end leaving. 57 divided by 2 = 28.5m per minute times 60 gives 1.71kph or 1.06mph. What was your working for a full length (72ft) boat getting through at 0.8mph? By my working a full length boat would be doing 1.2mph or 33% faster than your estimation.

[Ian Mac]

Two things,

Advice for the passage of Harecastle or any other tunnel for that matter, this was given to me by Charlie Atkins and has always worked for me. Your a big lad he said, you should always wear a hat and always lean forwards in the hatch. If your on a modern boat with wide open spaces around the tiller, have chair or something forwards of the tiller to lean on (do Not sit down!!)

The logic behind this is that if you are leaning forwards and your hat touches the roof, your natural reaction is to duck forwards, if you are leaning forwards already, so you stay on the counter. If you are upright or leaning backwards on the tiller, then you duck backwards and could fall off backwards.

 

I always understood the definition of a tunnel used by the old civil engineers was any structure though which you pass where the length is great than five time the arch circumference. This means lots of motorways crossings are certainly bridges.

 

It is easiest to steer in any tunnel the faster you go, if you are going too slow the boat will not self centre, so always go as quick as you feel safe going. Having said that some boats have really bad hull shapes and they do not swim well at speed in or out of a tunnel, interestingly they also appear to pick up loads on the blades as well. One of the hardest tunnel to pass through is Standegde but one of the best trips through that I have had was with a guy who did it in just over an hour. I know Terry and Fred and the other chaperones can do it quicker, but they have done it many hundreds of times not turned up for the first time like this guy had.

I personally find it really hard if I have to slow down in a tunnel so we always give at least 10mins start for the other boats when going north through Harecastle and it would not be the first time when that wasn't long enough. And as has been pointed out watch out for the tunnel doors at the south end, it can be very spectacular to open them with your bows - been there done that. The keepers don't expect sub 20 min passages. and even with the fans on you can't see the doors till your on top of them when the mist is rising of the water.

[Loafer]

A picture where the colours have become highly compromised over the years, but what it looked like when we approached it shortly after construction.

 

 

 

I'd like to try to do summat with that pic, Alan. Can you give me a digital copy to play with? All privacy and rights to you of course.

[David Mack]

Similar quick calculation, if my boat is 18m long (not a full length boat) and the tunnel is 21m then I'm going to cover 57m between the pointy end entering and the roundy end leaving. 57 divided by 2 = 28.5m per minute times 60 gives 1.71kph or 1.06mph. What was your working for a full length (72ft) boat getting through at 0.8mph? By my working a full length boat would be doing 1.2mph or 33% faster than your estimation.

If your boat is 18m long and the tunnel is 21m then you're going to cover 21m between the pointy end entering and the pointy end leaving and another 18m between the pointy end leaving and the roundy end leaving, making a total of 39m between the pointy end entering and the roundy end leaving.

[___]

If your boat is 18m long and the tunnel is 21m then you're going to cover 21m between the pointy end entering and the pointy end leaving and another 18m between the pointy end leaving and the roundy end leaving, making a total of 39m between the pointy end entering and the roundy end leaving.

 

Correct. Length of tunnel plus length of boat. Unless you have some sort of concertina boat that magically compresses to zero length in each portal.

 

JP

[Graham Davis]

It's in or was in GC/RC 5603

 

It takes an S&T man to read standards

 

But did we "bobbies" get sight of that?

Probably not since they liked to keep us in the dark and feed us bull excrement!!

[system 4-50]

I remember many years ago navigating more than one tunnel by keeping the bow sliding along one side of the tunnel with the stern a few feet off it. By side of the tunnel I mean at water level, not the masonry. The tunnel was lined with wooden baulks.

This was in hire boats.

 

Is this a legitimate way to travel today?

Do all tunnels have a wood-lined side?

Is there a risk of getting a nasty scratch from a projecting bolt-head today? I'm in my own boat not a hire boat!

[RLWP]

They seem to have wood along once side with chains hanging below, so people falling in have something to hold on to

 

I wouldn't navigate a tunnel that way, it isn't hard to do without rubbing along the side

 

Richard

[Guest]

system 4-50, on 20 Mar 2016 - 1:09 PM, said:

I remember many years ago navigating more than one tunnel by keeping the bow sliding along one side of the tunnel with the stern a few feet off it. By side of the tunnel I mean at water level, not the masonry. The tunnel was lined with wooden baulks.

This was in hire boats.

 

Is this a legitimate way to travel today?

Do all tunnels have a wood-lined side?

Is there a risk of getting a nasty scratch from a projecting bolt-head today? I'm in my own boat not a hire boat!

 

I personally couldn't see that working in Harecastle. Our Cabin front made contact with the wall/roof before the hull touched any of the side due to the profile in there which varies quite considerably. So you might get away with it in some tunnels but not Harecastle and certainly not some of the others with low roof profiles.

Edited March 20, 2016 by MJG

[GreyLady]

Thanks for the replys all, I guess I post a lot of stuff about stuff at the moment.

 

Thanks for putting up with me.

 

I still like the idea of these strips on the roof though.

 

It's got to be better than pram wheels on the corners.

 

You know what in 3 years I might be reading my own posts and thinking what a plonker.....☺

[John Holden]

 

You know what in 3 years I might be reading my own posts and thinking what a plonker.....☺

 

You'll probably be thinking that half way through your first passage of the Harecastle

[GreyLady]

You'll probably be thinking that half way through your first passage of the Harecastle

Recon you might be right John.

[John Holden]

My first time through all I hit was my head!

[GreyLady]

My first time through all I hit was my head!

I would rather hit my head than prang the boat Lol

 

My dad bought two hard hats from Wickes today.

 

£15 each but they made a boo boo at the till and we got them for £3.99 each.

 

Bargain.

 

Edited : arggghhhh autospell

Edited March 20, 2016 by GreyLady

[John Holden]

.

Hard hats, good idea but make sure you put a lose drawstring on them so that when they hit the roof they flip down onto your back and don't end up in the cut

[bizzard]

.

Hard hats, good idea but make sure you put a lose drawstring on them so that when they hit the roof they flip down onto your back and don't end up in the cut

They do float nicely if they land the right way up.

[GreyLady]

.

Hard hats, good idea but make sure you put a lose drawstring on them so that when they hit the roof they flip down onto your back and don't end up in the cut

Good advice John though me being a worrier thinks I might end up following the hard hat and a draw string into tha cut. Lol

They do float nicely if they land the right way up.

If you see a floating hard hat give it a knock it's prolly me.

Edited March 20, 2016 by GreyLady

[John Holden]

They do float nicely if they land the right way up.

 

That's the danger! You fall in trying to rescue your £3.99 hat

[Wanderer Vagabond]

They do float nicely if they land the right way up.

Don't they float both ways up? (bit unstable rounded side up though!)

[GreyLady]

Anyway I bought a hard hat and a decent cree headlamp, obviously I won't use the headlamp in harecastle tunnel unless theirs problem.