latter case the danger exists that the chain will continuously be tensioned again and that the forces are inadvertently increased thereto a tension limiting means 21 38 as illustrated in fig5 is designed which after pretensioning at the desired tension will block the passage of the chain in direction p to accomplish this links 21 and 22 are added to the pretensioner 8 when pulling on chain 26 point 24 and 25 tend to pull point 23 in one extended line this is stopped by a pack of belleville spring washers 27 when exceeding the spring pressure blade 28 of link 21 and blade 29 of link 22 will be pulled apart pawl 30 is then released from arm 31 a spring 32 will turn shaft 33 90 u00b0 whereby the blocking 34 of pin 35 is released at the same time by pawl 36 a smok buoy will be released and float up to the surface of the the sea this is the signal to lower the pretensioner the tensioner on the chain 26 will disappear and pin 25 will now be pressed out by the spring 37 also the pawl 38 is released and has blocked by means of a spring the return p of the chain 39 it is illustrated by fig5 that when chain 39 is hauled by means of the wire 40 to the ship the pretensioner will not slip down the chain finally it is observed that what.