Quick Q. What do you call those hooks that allow you to hook chain

[Ross1]

The strop and hook (as pictured above in another reply) is often called a snubber line/anchor relieving strop. As someone else mentions it hooks between the links and the rope is made off on a cleat! I use them regularly and have never had a problem! The primary use of them is to take the pressure off of the windlass as the windlass should never be relied upon to hold the anchor. A windlass often works with a friction clutch and can come loose/and or the bushes wear!
(no-one wants their anchor running free at 0400 in the morning!!)

 

[ShipsWoofy]

indeed, but I am not looking to use it for a snubber, I am trying to keep the rode off the centre roller by having a quick-rig bridle. By having a length of rope attached to the port hull cleat and the chain paid off the starboard hull; as enough chain is let out, we will hook through the chain from the rope on the the port hull and pay out more chain until the bridle comes centre between the hulls.

I would much rather have a long hook that is something like one of those hooks for lifting snagged anchor rodes to slip through a link. Those tippy hooks are the wrong shape though, something more U shaped that will be unlikely to drop out if the tension comes off.

I thought this would be a simple item, maybe I should look at a gaff and blunt the point off.