Take a look at Help Anybody know how to manipulate the chain and chain tensioner on a V12 HE - #28 by MarekH
This shows where a “stretched” chain sits and where a brand new chain sits. If your chain is loose and the tensioner broken, then it is “front timing cover off” time. You should be able to slip your hand down the Abank side and verify this. The chain should be strongly tensioned, not just lightly pushed across to the middle of the engine block. Note in the pictures how a brand new tensioner is strong enough to push the old
(oily) chain all of the way across and keep it tight even though that means it is rubbing on the engine block bolts. The new (clean) chain being “shorter”, is under more tension than that and sits more outboard.
kind regards
Marek