That word “harness” reminds me of something you would do to a horse, so I went over to DICTIONARY.com to look at all the meanings of the term “harness.”
Note: The following text snippet is a quote:
har·ness
–noun
1.
the combination of straps, bands, and other parts forming the working gear of a draft animal.Compare yoke1 (def. 1).
2.
(on a loom) the frame containing heddles through which the warp is drawn and which, in combination with another such frame or other frames, forms the shed and determines the woven pattern.
3.
the equipment, as straps, bolts, or gears, by which a large bell is mounted and rung.
4.
Electricity. wiring harness.
5.
armor for persons or horses.
–verb (used with object)
6.
to put a harness on (a horse, donkey, dog, etc.); attach by a harness, as to a vehicle.
7.
to bring under conditions for effective use; gain control over for a particular end: to harness water power; to harness the energy of the sun.
8.
Archaic. to array in armor or equipments of war.
—Idioms
9.
in double harness. double harness (def. 2).
10.
in harness,
a.
engaged in one’s usual routine of work: After his illness he longed to get back in harness.
b.
together as cooperating partners or equals: Joe and I worked in harness on our last job.
Opinion: Looks like definition 7 is the definition for the terminology as used in the statement in post no. 1.