On the other hand, military avionics has used waxed nylon cord
(usually dyed black) and made under a MIL SPEC since the 1950s,
prinicipally because it was a neat, cheap way to bundle up wires
that were not otherwise clamped together.

Here's my take on this (I laced a lot of wires
in the 1950s).

Wiring *harnesses* were made to facilitate
interconnection in equipment. Boards of
plywood with a drawing of the harness glued
on were the pattern, and finishing nails used
as guides for the wires. Wires were laid into
this guide according to a printed list. These
wires were usually pre-stripped and tinned.
Then the wires were soldered to connectors
when appropriate, and finally it was laced up.
This served both to constrain the wires, and
to make the harness easier to handle while
it was installed in the equipment. The stitches
or knots had to be done precisely according
to a MIL-Spec. It wasn't a lot of fun, and I
can remember rush jobs where everybody
from the lowest technician (me) to the engineering
manager worked long hours to make those
harnesses! Sure looked nice when it was done!

BTW, we only used white waxed nylon.

73, John - K6QQ

Now we all know where they got the idea for dental floss !

Waxed nylon lacing cord is great for spot-tying small
Teflon-insulated wire bundles.

In article , lenover21
@aol.com says...

Ahem...Boeing is not necessarily a good source for wire bundles
that are "safe." See the NTSB report on the air liner that blew up
just outside of NYC over the bay...especially the part investigating
wire bundles going through a fuselange gas tank.

I never claimed they were perfect. I was using my experiences and
observations as a supporting point.

On the other hand, military avionics has used waxed nylon cord
(usually dyed black) and made under a MIL SPEC since the 1950s,
prinicipally because it was a neat, cheap way to bundle up wires
that were not otherwise clamped together.

I have no doubt that the military came up with some sort of lacing
machine. ;-)

I bought a package of 100 Ty-Raps at DoItCenters couple months ago
to hold up an outside planter's drip irrigation tubing to an aluminum
awning. Tubing is very soft, about 1/4" diameter. 8-inch tie wraps,
standard white nylon material. No problem. No stoppages, no
damages, but didn't try to put a full arm's strength into completing the
tie. :-).

snip remainder

The reference to 'fragile' coaxial cables was made in regards to
the Teflon-jacketed stuff in use in aircraft, not conventional RG8 or
others. I should have clarified that a bit.

It was found that some types of insulation (notably Kapton) show a
greater sensitivity to arcing if they have been nicked or scored, even
slightly. Ty-wraps, if not properly used, are more likely to do this
than lacing, especially in a vibration environment. This is why they are
not generally favored for aircraft wire bundles.

While I agree that neatness was certainly one of the reasons, it
was not the only one.

I would be most interested to hear what anyone working in CURRENT
wire design on aircraft has to say about the subject.

Keep the peace(es).

--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"

On Wed, 19 Jan 2005 04:27:41 GMT, "Don Kelly" wrote:
[snip]
|Cable lacing was (and is?) common for control wiring in control panels etc.
|in the power industry. In that case the signals involved were either 60Hz or
|DC and electromechanical relays and meters were used. coupling between
|circuits was a non-issue. However, with the advent of solid state devices,
|coupling became a problem. One major manufacturer considered a "diode tester
|to be a 15 ft lead to a switch or contactor cabled with a lead tied to the
|diode. - Open the switch- blow the diode. Wiring was neat and elegant and
|easy to follow. Circuit diagrams were accompanied by "back of panel"
|diagrams of the wiring to facilitate maintenance/repairs.

At Hughes, we didn't do "lacing", but used "lacing cord" (flat, waxed,
nylon) by the mile. We used spot ties, a precursor to today's cable
ties. These were clove hitches around the wire bundle, secured with a
square knot. In the production (missile) area, the ends had to be
cut, but in the engineering and test equipment area, we would "neaten
things up" by melting the ends into the knot with a soldering iron.

Since all the wire was teflon insulated, the ties could be slid along
the wire bundles during construction. While still a technician, I
once wired a programmer for some TOW missile test equipment. This was
back when the highest level integrated circuit was a 7490 decade
counter. The unit was basically a timing generator that had four PC
board card cages, 30 cards per cage, 44 pins per board, six 72-pin
cable connectors and a 24-column x 48-row patch panel. Damn near
every pin was used. Timing sequences were determined by ANDing and
ORing signals together via the patch panel and then setting or
resetting J-K flip-flops. So there was a lot of redundant wiring,
ie. one card cage might have 30 identical NAND gate boards.

We used ten wire colors, same as the resistor code, and prided
ourselves on having every wire bundle identical throughout its length
and to its neighbor. Black wire next to the brown wire next to the
red wire.....