Page 101 - Buck Tilton - Outward Bound Ropes, Knots, and Hitches 2 ed.

Take the working end down through the loop in

the knot through which the standing part passes.
Tighten by pulling on the standing part.

Transom Knot

A USEFUL KNOT FOR TYING TOGETHER TWO CROSSED
PIECES OF RIGID MATERIAL

Back when lashing was more popular in camping, when

limbs of trees were freely lopped off and tied together as
frames for tents and tarps, the transom knot (called by

some the strangle knot) found many uses. It is still a handy
knot, useful for securing a pole between two trees from

which gear may be hung or to which the high end of a tarp
may be attached for shelter.

Transom Knot: Step 1