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Post by Organgrinder on Nov 9, 2011 14:28:50 GMT
Just had an idea I thought I would share to see whether you all thought it could work. If it was workable it would make towed recoveries of soapboxes and sidecar outfits quicker and safer with minimal cost.
The idea is to use an inertia reel seatbelt as a tow strap. If each cart was fitted with a seatbelt socket at the front (on the centreline) and an inertia reel at the rear the carts could be linked very simply in a chain. It wouldn't matter within reason how many carts were linked and there would be no spare rope to get tangled up if only a few carts were being towed.
I am sure the breaking strength of the webbing used would be far higher than we would need. Because the reel would wind in any slack automatically there would be no danger of carts running over the tow as happens now and gaps between carts would be uniform, making it very simple for event organisers. We would probably have to disable the ratchet that normally stops the strap being fully extended. The event organiser would simply have to equip each tow car with a seatbelt strap and "male" connector to join to the first cart in the line. the rest would look after themselves.
Any thoughts?
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Post by Scottish Cartie Association on Nov 9, 2011 15:13:07 GMT
Wouldn't that make each cartie a load bearing part of the tow line?
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Post by Organgrinder on Nov 9, 2011 15:22:37 GMT
It would - (and I know we have been here before!) but it wouldn't be hard or expensive to make sure that the bit between the loaded points was strong enough to take the strain.
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Post by Scottish Cartie Association on Nov 9, 2011 16:15:40 GMT
it wouldn't be hard or expensive to make sure that the bit between the loaded points was strong enough to take the strain. I seem to remember that wasn't quite what you said last time we talked about it. Anyway - neat idea in theory. In practice, however, I suspect it might be a bit tricky to get everyone to comply. Everyone would want to be a special case. Also - are all seatbelt clips a standard fitting? Anyway - as it happens we're currently working on the new rules for Cairngorm and there is a provision in the current draft for all teams to provide their own tow rope to link to the cartie in front. Not quite as suggested, but will still take an burden off the event organisers. Should have the final version available early next week.
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Post by Organgrinder on Nov 9, 2011 16:40:58 GMT
Last time we discussed this I was acting as Dick's mouthpiece! My own views were somewhat less conservative.
I'm not sure whether all seatbelts have standardised couplings, but it would be easy enough to either find out. If they are not we could specify belts from a commonly available donor car, say for example a Ford Fiesta made between 2000 and 2005, to ensure compatibility.
From the organiser's perspective, I like the idea of putting the onus on competitors to supply the towing equipment.
Perhaps the idea of integrating the tow gear into the cart's construction is a bit too far to go in one jump, but I still think it would be quite neat and make the marshal's job much easier because they wouldn't have to grovel about under the carts. It would also eliminate those silly accidents that occur while towing that arise because the ropes get tangled up with the cart's wheels.
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Post by andy on Nov 9, 2011 22:55:34 GMT
I Like Organgrinders idea of a simple push in attachment, certainly would make it easier for the hook up guys who have a thankless task and certainly don't get enough credit for the excellent job they do.
Each cart then becoming a load bearing part of the tow would be a concern to me, although if carts were built with this in mind, then that shouldn't`t be such an issue.
Fitting the inertia reel should be a fairly straight forward procedure too, just bolt it onto a strong part of the cart.
The main problems I can see with the existing methods most events use are 1. Carts un hooking themselves..this can be avoided by using "D shackles" or similar ( tho these are a bit tricky to attach)but once in place they will not come off
Spring hooks ..are easy to attach and seem to work best if they are put on to the tow eye facing upwards.
2. The tow rope getting caught under the back wheels of the carts in front. This could be avoided by having a secondary guide hook on the back of each cart.
I think a good solution would be to make all towing eyes easily accessible ie right on the front centre of the cart and make it mandatory to have rear guide hooks.
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Post by kingkay on Nov 9, 2011 23:02:45 GMT
Just to let you know all seatbelt connectors are different. Well they’re certainly not all the same anyhow. Most will only work if the real is extended vertically too. Trying to attach them horizontally causes the inertia bit to lock up.
Having helped with cart recovery at Dalby and at Belchford I agree the current system is a right pain. I guess it would be a bit crappy to fail carts on inspection if the towing eye is not up to speck but it would certainly stop some of the problems, at Dalby we got a puncture when the car in front came off the tow eye and crashed into us, some other cars came off too - dangerous and slows everything down.
If a minimum ground clearance was enforced and the towing eye was in the middle where it should be and the size and opening are as asked for in the build spec then the ropes wouldn’t get worn or tangled and the connectors wouldn’t come undone. Or am I just being a right Nazi.
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Post by andy on Nov 10, 2011 10:15:07 GMT
King kay.......Ich konnte nicht mit dir nur zustimmen !!
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Post by Scottish Cartie Association on Nov 10, 2011 11:55:38 GMT
The SCA's current procedures for towing and tow ropes is available for download from scottishcarties.org.uk/downloads and covers a few of the points mentioned above. It's due for a major revision though, as we're going to be moving to a "daisy chain" system where each team provides their own tow rope and fittings for 2012.
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Post by kingkay on Nov 10, 2011 19:59:22 GMT
If you link 6 cars together you could be pulling over a tonne and if there’s slack at the start the snatch weight will be considerably higher. If people don’t follow instructions to put a tow eye of the right size, height and material it can be a pain for the marshals, but if the don’t do a good job on their fixings with daisychaining and something breaks everyone else can be buggered up too. Two fixings per car will make it twice as slow to connect / disconnect and if they put a crap fixing on front and back it makes things twice as hard. It would hack me off if my welding failed and broke my cart, but it would hack me off more if it was caused my someone else’s crap build.
What about supplying the tow eye in with the enrolement fee and making bloody sure everyone knows they can’t race unless it’s fitted to the rules. A minimum ground clearance and a rear rope guide would stop the ropes getting knackered wouldn’t it?
befolgen Sie die blutigen Richtlinien
Toby.
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Post by Scottish Cartie Association on Nov 11, 2011 0:46:28 GMT
Here's what we'll be doing at Cairngorm in 2012. Notice that the tow ropes link to each other, so the carties are not load bearing parts of the tow chain.
To avoid problems with variable quality of ropes made by teams, we'll have a stock of ropes, shackles, etc and available for purchase at the event.
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Post by neils on Nov 11, 2011 9:23:21 GMT
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Post by Scottish Cartie Association on Nov 11, 2011 10:13:59 GMT
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Post by leew on Nov 11, 2011 15:31:51 GMT
Some good ideas there. I'm not very keen though on the entire weight of the cartie 'train' being put on the towing hook of the front cartie though as it would put alot of stress on the tow point and also the rest of the chassis of that cartie and it could fail. Many of us are not professinal welders and thus our welds may not be as strong as they could be. On the flip side, one of the things which causes me to worry with the current system of hooking all the carties onto a single length of rope is that if the towing hook on the cartie infront of me failed then it could smash into me, or rather I would smash into it as I would still be moving. Don't think it's actually happened yet. Most of the rope breaks I have seen so far have been due to the rope fouling the road surface. Maybe a minimum height for the tow hook and quide should be specified, like the centre of the hook should be between 50mm and 150mm off the ground? I know that would not be possible with some carties due to low ground clearence (c12 springs to mind), in that case the rope could be passed though the cartie (providing it does not intefear with the steering etc) and to avoid delays in hooking up, the length of rope could be already hooked onto the front towing hook, passed through the cartie and the guide and the excess stowed in a 'boot' or simular compartment. Also, how do you define a "permanently attached" tow point? Does this mean it has to be welded on? Would an M10 eye bolt fitted with a nylock nut not pass?
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Post by Scottish Cartie Association on Nov 11, 2011 16:03:22 GMT
Some good ideas there. I'm not very keen though on the entire weight of the cartie 'train' being put on the towing hook of the front cartie though as it would put alot of stress on the tow point and also the rest of the chassis of that cartie and it could fail. Are you refering to the SCA's new rules? If so, you've misunderstood them as that doesn't happen. Each to rope section is attached to the rope in front of it. The cartie chassis is not load bearing, and the cartie's front tow point only needs to take the load of the cartie itself. Maybe a minimum height for the tow hook and quide should be specified, like the centre of the hook should be between 50mm and 150mm off the ground? That was considered, but it wast thought that it would produce far too much moaning and would also rule a lot of carties out. In fact, there is no requirement for the rope to pass under the cartie. It just needs to be safely routed from front to rear - perhaps over the top of the wishbones/axle beams. But if you do route the rope under your cartie, it's your rope that gets mangled. Also, how do you define a "permanently attached" tow point? Does this mean it has to be welded on? Would an M10 eye bolt fitted with a nylock nut not pass? Permanently attached means "during the event". Bolted on would be fine, provided you didn't expect it to be bolted on before each tow.
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Post by leew on Nov 11, 2011 16:51:04 GMT
Don't think I've misunderstood, maybe a picture shows it better?
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Post by Scottish Cartie Association on Nov 11, 2011 17:16:45 GMT
That' exactly it. I don't see why you think the entire weight of the cartie 'train' is being put on the towing hook of the front cartie.
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Post by leew on Nov 11, 2011 17:23:52 GMT
Not with that arrangement no, but it would be with the seatbelt idea.
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Post by brillo451 on Nov 11, 2011 23:04:39 GMT
Please forget about the seatbelt idea it is far too much grief, I've fitted a different seat belt arrangement to the VW when I was moving kids around for the school and wanted to fit a proper belt instead of a lap belt two of the one's I tried seemed to latch properly and subsequently released when I had flight cases strapped on to the rear seat thank goodness it wasn't a child...You have been warned
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Post by leew on Nov 12, 2011 9:39:11 GMT
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