20mm Plastic Trunking

[securespark]

'Firm hand-manipulation'

I'm pretty sure I tossed what I had

Ooohh, Matron!

 

[JohnW2]

'Firm hand-manipulation' I'll go with! I wasn't going crazy with it, by any means.

Found mine! Only you can know quite how firm your "firm hand-manipulation" is, but (if you'll forgive the very crude ad-hoc 'test jig'!), how does it compare with a club hammer, I wonder? (It really is 'free hanging' with nothing supporting the cable or hammer)....

I suspect this is the same stuff that BAS remembers. The outer sheath is the problem, which is really quite like plastic water pipe.

Kind Regards, John

 

[rsgaz]

Well, that is an odd cable, granted! It looks so thick, too. Does the sheath contain woven nylon/kevlar strands or something, I don't see how it can be so rigid?!

I'll try and knock up a similar NASA grade jig.

 

[JohnW2]

Well, that is an odd cable, granted! It looks so thick, too.

I think it's 2.5mm², and it's about the same OD as 3-core 2.5mm² SWA. In fact, I kept finding bits of SWA and thinking it was the HiTuf utill I eventually found the real thing.

Does the sheath contain woven nylon/kevlar strands or something, I don't see how it can be so rigid?!

No armour, strands etc. - just solid, very tough, fairly 'waxy', 'plastic' - as I said, not dissimilar to modern plastic plumbing pipe in consistency etc. (indeed, including rigidity!). The material reminds me of something, but I can't think what (other than the plumbing pipe)!

The outer sheath is difficult to cut with a Stanley knife and, although it's a technique likely to damage the cores, a hacksaw very rapidly gets clogged by the plastic. Believe it or not, a pipe cutter, used judiciously, seems to be about the best way to get through the sheath!

BAS, is this the same stuff you remember?

I'll try and knock up a similar NASA grade jig.

Fair enough. Is this a competition?

Kind Regards, John

 

[rsgaz]

how does it compare with a club hammer, I wonder?

I don't have a club hammer to hand, nor a filing cabinet 'jig', but a 24oz hammer with the cable poked inside a ladder rung results in gravity winning, rather than the cable winning in your demo...

It would basically be vertical if my off-cut was longer.

the same OD as 3-core 2.5mm² SWA

That really is thick, then! The OD of this is 9.5mm.

The outer sheath is difficult to cut with a Stanley knife

I wouldn't use a knife either, not because the sheath is too tough, but the risk of going through into the insulation. Once you're through the black sheath, the white layer offers no mechanical resistance at all. I use a Jokari to ring and slit it, all done in 5 seconds, the white 'filler' then just crumbles...

It almost sounds as though your early Hi-Tuff was "suitable for direct burial", as I don't think a spade could go through it!

 

[ban-all-sheds]

I suspect this is the same stuff that BAS remembers.

It is.

The outer sheath is the problem, which is really quite like plastic water pipe.

It is.

 

[ban-all-sheds]

BAS, is this the same stuff you remember?

AFAICT.

But I'm trying hard to forget it.

 

[ban-all-sheds]

I wouldn't use a knife either, not because the sheath is too tough, but the risk of going through into the insulation. Once you're through the black sheath, the white layer offers no mechanical resistance at all. I use a Jokari to ring and slit it, all done in 5 seconds, the white 'filler' then just crumbles...

That looks so much like some SWA I've used that I'd swear the manufacturer started out with that and then turned it into SWA or hituf.

 

[JohnW2]

I don't have a club hammer to hand, nor a filing cabinet 'jig', but a 24oz hammer with the cable poked inside a ladder rung results in gravity winning, rather than the cable winning in your demo... I wouldn't use a knife either, not because the sheath is too tough, but the risk of going through into the insulation. Once you're through the black sheath, the white layer offers no mechanical resistance at all. I use a Jokari to ring and slit it, all done in 5 seconds, the white 'filler' then just crumbles...

I don't think that approach would have worked with this old stuff - it was far more difficult than you describe. As you can hopefully see here (cut with hacksaw, and pretty grim photo), there is no 'inner layer', white or otherwise. The outer (and only) sheath made out of this very hard, almost rigid, plastic is all there is, and it's actually moulded around the cores - it really is/was a major challenge to get the black stuff off without damaging the insulation of the cores ...

It almost sounds as though your early Hi-Tuff was "suitable for direct burial", as I don't think a spade could go through it!

Well, to be serious, I think one would have to be pretty heavy handed with the spade (and might need to 'sharpen' it first!) to get through it in one blow!

If you were that interested, and were prepared to PM me with a postal address, I'd be happy to send you a few inches to look at and play with.

Kind Regards, John

 

[rsgaz]

cut with hacksaw, and pretty grim photo

Strangely, I was going to ask you for exactly that picture, thanks! I cut mine with ordinary side cutters, I didn't even bother getting out proper cable shears!

But that seems to just raise more questions. I thought NYYJ was always solid conductors(even in rather large CSAs), but I can clearly see 7 strands on yours. I'm assuming yours doesn't say BASEC or a BS number anywhere either? I just found this old page about it...

https://web.archive.org/web/2008042...universe=consult.index.questions&fullsize=yes

Seeing as it "does not conform to a published standard", I guess Draka can change the design whenever they fancy! (after numerous complaints 20 years ago of it being utterly useless, I assume!!). Not that the stuff I used was Draka branded though, a cheap copy I suspect.

I'd be happy to send you

No thanks, but thanks!!

 

[JohnW2]

But that seems to just raise more questions. I thought NYYJ was always solid conductors(even in rather large CSAs), but I can clearly see 7 strands on yours.

To be fair, I have no recollections of TLC having claimed that it was NYYJ - they just sold it as HiTiff.

I'm assuming yours doesn't say BASEC or a BS number anywhere either? I just found this old page about it... https://web.archive.org/web/2008042...universe=consult.index.questions&fullsize=yes
Seeing as it "does not conform to a published standard", I guess Draka can change the design whenever they fancy! (after numerous complaints 20 years ago of it being utterly useless, I assume!!). Not that the stuff I used was Draka branded though, a cheap copy I suspect.

I thought mine was unmarked, but having now looked more carefully, there are (very difficult to read) markings. It's definitely Draka. I'm still trying, but the closest I've got to reading it so far is "DRAKA ?????? CABLE ????? 600V/1000V ????"

No thanks, but thanks!!

Fair enough, but the offers stands!

Like BAS, I don't think I used (or tried to use) it more than two or three times before I got top the "never again" point. However, at least one example remains, of cable to an outside light which I probably installed about 25 years ago ... this shows the best I could do at bending it at the time (fortunately it's not in a particularly conspicuous place!) ....

Kind Regards, John

 

[rsgaz]

best I could do at bending it at the time

You're certainly right then about it being 'worse than SWA' in that respect!!

 

[JohnW2]

You're certainly right then about it being 'worse than SWA' in that respect!!

Indeed. The link you posted described it as ".... extremely resilient in most applications almost as good as SWA..."!

Kind Regards, John