Frankydobo:
Ah the old Susie chestnut (spelt Susie not with a Z), here we go, SUSpended Insulated Electrical Lead or for short Susie Lead. If you weren’t around in the late 50’s early 60’s in transport you won’t recall that the first coiled lead attached from Unit to Trailer was the electrical lead, the air lines were still long hoses with Palm Type couplings that often got snagged or worse, we didn’t seem to go for the Pogo Stick affair the Yanks used to keep lines held up. The early coiled electrical leads were thick rubber coated and had quite small coils and were heavy compared with later ones. So that is your actual Susie, I can only presume the industry, once Poly nylons had started to be used more for many items, that Nylon (plastic as we called them) air lines could also be manufactured and used as the electrical lead had, in effect suspended and able to avoid the problems the long air lines previously had, although we know from experience the coiled airlines were not entirely free from snagging or getting dirty.
Now looking into this I came across a Law Suit where a well known company was using Susie as its Copyright logo and another manufacturer was objecting as it said the term was a generic one used to describe the airlines, now it was the Red, Yellow, Blue airlines they were concerned with I’m not even sure having read the case that both companies knew the electrical lead was coiled before the ones used to pass air. I also don’t know the outcome of the case it wasn’t covered on the piece I found on the internet. By the way before anyone checks I’ve searched old Comm Motor mags and they only refer to the later made airlines mentioned as Susie’s. It seems the term came into use probably by whichever manufacturer made the first coiled electrical leads or the guys tasked to sell them to the industry and the term took hold when the first plastic leads appeared until it was used to describe all the lines attached to unit and trailer right up to today.
Nearly done, to answer briefly another query, the Red line (Emergency) supplies air from Unit to Trailer air tank in a constant feed and releases the trailer brakes. The Yellow line (Service) supplies air to the trailer brakes when the Unit foot brake is pressed applying trailer brakes. The Blue line (Secondary) supplies air to the trailer brakes when the Secondary brake in the cab is applied. Many types of Secondary brake were used over the years, some mounted separately some in the same modular unit as the hand/park brake. Hope this shed some light but please don’t put a Z in Susie,its like saying ‘I’ve had a Cheeze sandwich’ and that’s not right is it!Cheers Franky.
Very well done.
