standing rigging tangs

[BurnitBlue]

On all my previous boats the standing rigging was attached to the mast with eye terminals and clevis pins held by split pins. Not so on my latest boat which follows the "hook" system. Seems a bit flimsy and insecure to me just hooking the rigging into a slot in the mast. Even with a cover plate to stop it jumping out it seems unsafe from my previous experience.

Is this OK or have people experienced failure. The hook terminals on my rigging are like a shepherds crook. It bends out, then in again to form the hook. I was told this was to balance the line of "force" to prevent a tendency to unbend the hook.

I would be grateful for opinions please

 

[Kelpie]

What you are describing is a T terminal. Pretty common on boats from the 80s onwards I believe.
I share your distrust in them. There are examples of failed terminals (try Vyv Cox's website). The only I've owned that has them is my little 14ft Wanderer, and I've noticed that it's quite possible to get the terminal hooked in wrongly whilst stepping the mast- it will be held in the slot, but not at the right angle. This potentially puts a huge strain on the wire as it exits the terminal, because of the change in angle. Probably less likely to happen on a yacht as you'd be taking more time over stepping the mast, but worth watching out for.

I'm not really sure what the point of them is- maybe, like saildrives, they are slightly cheaper for manufacturers?

 

[Tranona]

Don't think they are any more or less prone to failure. Pretty universal these days - and have been for 30 odd years so if they were a disaster why would they still be used? The important things as ever is to check them periodically as with any other critical mast fitting and make sure the correct type type is fitted if replacing them. The advantage is mainly that they are simpler and easier to get stay angles correct than rivetted on plate tangs - which in themselves are potentially unreliable with rivets and clevis pins, and often tubes through the mast to locate them securely without crushing the mast wall.

 

[DownWest]

Don't think they are any more or less prone to failure. Pretty universal these days - and have been for 30 odd years so if they were a disaster why would they still be used? The important things as ever is to check them periodically as with any other critical mast fitting and make sure the correct type type is fitted if replacing them. The advantage is mainly that they are simpler and easier to get stay angles correct than rivetted on plate tangs - which in themselves are potentially unreliable with rivets and clevis pins, and often tubes through the mast to locate them securely without crushing the mast wall.

+1 I don't like the idea on basics, but they work.

 

[BurnitBlue]

I can believe it is cost reduction to be the driving force. What concerns me on my boat is the baby stay which is also a T terminal (thanks for the correct name). Some Moody owners have modified the baby stay to make it an inner forestay for a cutter rig. The better attempts have been to remove the baby stay fitting and place another slot higher up the mast above the cross-trees. The base rigging screw of the new longer baby stay (now inner forestay and baby stay combined is connected to the anchor well and the wire runs exactly parallel to the main forestay and looks quite neat.

Surely the mast attachment for the combined stay could not be a similar T terminal as a flogging sail would destroy the mast wall. So How did the owners attach it to the mast. The few write ups I have read definitely mention a new slot above the crosstrees Actually just above the spinnaker pole up-haul block which now serves as a cutter sail halyard.

Havn't talked to the owners just seen the boats so rigged. Any advice please how I can avoid cutting another slot in the mast wall.

Thanks

 

[Kelpie]

Have you tried the Moody Owners Association?

 

[Tranona]

I can believe it is cost reduction to be the driving force. What concerns me on my boat is the baby stay which is also a T terminal (thanks for the correct name). Some Moody owners have modified the baby stay to make it an inner forestay for a cutter rig. The better attempts have been to remove the baby stay fitting and place another slot higher up the mast above the cross-trees. The base rigging screw of the new longer baby stay (now inner forestay and baby stay combined is connected to the anchor well and the wire runs exactly parallel to the main forestay and looks quite neat.

Surely the mast attachment for the combined stay could not be a similar T terminal as a flogging sail would destroy the mast wall. So How did the owners attach it to the mast. The few write ups I have read definitely mention a new slot above the crosstrees Actually just above the spinnaker pole up-haul block which now serves as a cutter sail halyard.

Havn't talked to the owners just seen the boats so rigged. Any advice please how I can avoid cutting another slot in the mast wall.

Thanks

Selden produce a special fitting for installing an inner forestay in a new slot higher up. Not sure it is a good idea to replace the baby stay as that fulfils a different function to an inner forestay. the inner forestay is usually removeable and used just for a storm jib as required. The baby stay remains to support the mid part of the mast.

 

[knuterikt]

The T terminal plates are now in its 3 generation design due to the two first being to week.
Have a look at these pictures https://www.facebook.com/392393034192807/posts/1462503587181741/

 

[vyv_cox]

The T terminal plates are now in its 3 generation design due to the two first being to week.
Have a look at these pictures https://www.facebook.com/392393034192807/posts/1462503587181741/

The makers/designers of T-ball fittings seem totally unaware of the effects of fatigue. The T-balls shown on my website, the plates that correspond with them (no photos) and the one shown in the link have not failed due to weakness but due to fatigue. Adding a stress raiser, or the formation of one such as a corrosion pit, can lead to failure of items that have huge margins of safety.

 

[BurnitBlue]

Selden produce a special fitting for installing an inner forestay in a new slot higher up. Not sure it is a good idea to replace the baby stay as that fulfils a different function to an inner forestay. the inner forestay is usually removeable and used just for a storm jib as required. The baby stay remains to support the mid part of the mast.

Thanks, I have just downloaded the fitting. If it is the same as you suggested, this one is two "L" profile in stainless steel. A slot is cut in the mast then, the two "L" profiles are inserted in the slot then bolted together to form a tang. "_!!_".
I actually heard of using the baby stay as an inner forestay from the Moody Association. The inner forestay is kept in its new position and is also kept as a baby stay permanently. The distance between the old mast baby-stay fitting and the new mast baby-stay/inner forestay is only a few feet so it should do the same job. The baby-stay chainplate is effectively moved to the anchor locker wall (about three feet) It frees the deck space for a dinghy. The inner forestay sail halyard is the spinnaker pole up-haul which can also do both jobs when required. This DIY mod seems to be used on Moody 34/346 Moody 37/376. The old baby-stay chainplate is an abomination on all these models and causes the deck to lift and then rain water to rot and rust the fitting and under deck area. Lots of suggestion on the Moody web site to fix this and the cutter fix seems to me to be the best.
Thanks for the seldon mast tang link.

 

[BurnitBlue]

The makers/designers of T-ball fittings seem totally unaware of the effects of fatigue. The T-balls shown on my website, the plates that correspond with them (no photos) and the one shown in the link have not failed due to weakness but due to fatigue. Adding a stress raiser, or the formation of one such as a corrosion pit, can lead to failure of items that have huge margins of safety.

I can't pretend to know what a stress raiser is or if I have one fitted. Rigging was changed in 2007 so the T-balls should be new(ish). The word fatigue does raise alarm bells though. Hopefully the important rigging wires go to the masthead and should be clevis pin and split pin as of old.

 

[vyv_cox]

I can't pretend to know what a stress raiser is or if I have one fitted. Rigging was changed in 2007 so the T-balls should be new(ish). The word fatigue does raise alarm bells though. Hopefully the important rigging wires go to the masthead and should be clevis pin and split pin as of old.

All is explained here. http://coxeng.co.uk/metallurgy/fatigue/ The T-ball fittings shown are the later type, where the projected line of the swage passes through the contact point on the ball. In earlier designs it did not, with the result that the bend was put under increased stress. Many failed at this point. I have photos of some that I use in my talks but not on the website yet.

 

[BabaYaga]

Thanks, I have just downloaded the fitting. If it is the same as you suggested, this one is two "L" profile in stainless steel. A slot is cut in the mast then, the two "L" profiles are inserted in the slot then bolted together to form a tang. "_!!_".

That sounds more like the Wichard solution.
For the Seldén saddle type forestay fitting, google part # 508-099.

 

[BurnitBlue]

That sounds more like the Wichard solution.
For the Seldén saddle type forestay fitting, google part # 508-099.

Yes it looks like I downloaded the Wichard solution. I have just now downloaded the Seldenmast pdf catalogue. Looked at your suggestion 508-099 and that looks like a simple loop used against a halyard wrap. Further down the page there were fittings that looked more beefy and include both forestay and halyard sheave. I have not studied this on the catalogue yet but a quick look indicates that this fitting is just inserted into a wide slot and held in position by just two machine screws. This cannot be right surely, no internal mast backing plate for instance. I must be missing something so I will spend some time today studying the whole catalogue.

Wow on a bicycle. I am amazed a mast maker has so many part numbers and products.

 

[BurnitBlue]

All is explained here. http://coxeng.co.uk/metallurgy/fatigue/ The T-ball fittings shown are the later type, where the projected line of the swage passes through the contact point on the ball. In earlier designs it did not, with the result that the bend was put under increased stress. Many failed at this point. I have photos of some that I use in my talks but not on the website yet.

Thanks for the information on your web pages. I will watch out for the latest information about stress on the actual "hook" when you update the website. In the meantime from your website it appears that you even cover mast breaking metal fatigue on both the old through bolt tang system and the new (to me) T-ball fittings. But which is more prevelant? I would suspect that the T-Ball fittings have more failures than the old system but I could be showing my age and the expression "they don't make 'em like that anymore.

 

[BurnitBlue]

OK studied the Selden catalogue and it supports Tranona's opinion that it is a bad idea to use a baby stay as an inner forestay for a cutter rig. I forgot all about running backstays that would be needed to counteract the forces from a sail. The Selden catalogue is quite specific about this.

I still like the idea of moving the baby stay further away from the mast to free the space for a dinghy. Right now my dinghy is carried so far forward that it sits in top of the anchor windlass. If I move the base "chainplate" from its position now to the anchor well I could carry the dinghy close tp the mast. The question though is whether the T-ball filling will be OK with such a change in wire angle. It should be more efficient as a baby stay so is there any other considerations you can think off. On the other hand other folk have solved the baby-stay foredeck problem by using a "Y" fitting and using the conventional system of forward lower shroud to each side of the coachroof.

OOps I should have started this thread on the nut and bolt PBO forum. Maybe this thread can be moved over there

Anyway, thanks for the replies.

 

[Tranona]

The babystay is there because your boat does not have forward lower shrouds. Two reasons - cheapness and allows closer sheeting of the jib. It is not intended to carry any sail. Downside is that it makes tacking large jibs difficult and means space on foredeck is restricted - plus anchoring it securely to the deck is difficult. If you remove it you reduce support for the mast in the central section, although adding forward lowers will replace the support, but needs new chainplates and probably reinforcing internally.

 

[Kelpie]

Moving the baby stay forward on deck is going to make tacking harder.
I'm sure I've heard of forward lowers being added on Moody yachts. Not a small job though.

 

[BabaYaga]

I'm afraid I gave you the part # for the saddle only, correct number for the entire fitting is 517-905-01 (6mm stay) or 517-911-01 (7 or 8mm stay).
The advantage of this type of forestay fitting is that you don't need access to the inside of the mast (top box remaining on), this in contrast to the "nose" type fittings.

I have not studied this on the catalogue yet but a quick look indicates that this fitting is just inserted into a wide slot and held in position by just two machine screws. This cannot be right surely

It surely isn't.

 

[vyv_cox]

Thanks for the information on your web pages. I will watch out for the latest information about stress on the actual "hook" when you update the website. In the meantime from your website it appears that you even cover mast breaking metal fatigue on both the old through bolt tang system and the new (to me) T-ball fittings. But which is more prevelant? I would suspect that the T-Ball fittings have more failures than the old system but I could be showing my age and the expression "they don't make 'em like that anymore.

The tang would still be there today if they had put a toggle between it and the shroud. The absence of any means of articulation meant that any mast movement was accommodated by bending the tang.