TM Safety Chains

Good day all,

I'm curious about the safety chains on our unit.  The chain is one length, with only the center link bolted to the TM.  It is attached by one of the bolts which are installed to hold the tongue jack in place.

Is this normal for TM's?  I'm thinking about replacing it with heavier chains bolted to the tongue frame.

We are new (older) TM owners & appreciate the help.

Dan