The friendly 'dumb' truck questions thread

[Koyaanisqatsi]

Inspired by the same thread in the biker section, which has proved to be very helpful, I thought I'd try starting a truck equivalent. For every question, no matter how small, I'm sure there will be a helpful answer.

I'll kick off by saying that we've just got a new artic unit which is 6x4, double drive with a tag axle and 80ton fifth wheel with a huge loader crane on it. Having not driven one before (tag axle, that is), what are the pros and cons of a tag axle rather than midlift? I assume much better turning circle (when empty at least), but need to reverse under trailers with the axle / air down otherwise the rear mudguards scrape against the greasy underside of the trailer? Any other tips?

And why do all the scrap / recycling lorries have a taglift, is it simply for manoeuvrability around tight sites?

[Stussy]

Tags are better for rough terrain or where more traction is needed, and as you said, better turning circle with it lifted. Mid is better for long distance as it’s more stable.
As for backing under a trailer, it’s worth lowering the air regardless of which type it is, then lifting it once the 5th wheel is under and the hitch up

[Smint]

Tags for maneuvering and grip.
Tags can be an issue with older and shorter (ie urban) trailers due to fifth wheel position.
Downside of tags are typically a worse ride when empty, though in reality the really short wheelbase tractor units of the 70s were the worst boneshakers one could hope to experience, a modern tag unit offering limo ride quality in comparison to those.

6 x 4 is interesting, presumably drive is disconnected from the rear axle when in the raised position?

Edited by Smint on Saturday 30th August 22:35

[Its Just Adz]

Smint said:

Tags for maneuvering and grip.
Tags can be an issue with older and shorter (ie urban) trailers due to fifth wheel position.
Downside of tags are typically a worse ride when empty, though in reality the really short wheelbase tractor units of the 70s were the worst boneshakers one could hope to experience, a modern tag unit offering limo ride quality in comparison to those.

6 x 4 is interesting, presumably drive is disconnected from the rear axle when in the raised position?

Edited by Smint on Saturday 30th August 22:35

At my previous job we had 6x4 Volvos, used for landfill work.
So yes, the drive from axle 2 disconnected somehow when the tag was lifted.
They were brilliant off road.

[Smint]

Its Just Adz said:

At my previous job we had 6x4 Volvos, used for landfill work.
So yes, the drive from axle 2 disconnected somehow when the tag was lifted.
They were brilliant off road.

Much obliged to my learned friend, wonder how that disconnected, hydraulic drive to the tag or the rear prop disconnected electrically once the tag lifted?

For those of us stuck with standard mid lifts, a trucker doing offroad stuff posting on trucknet explained about the dumping of all trailer air and raising the tractor unit to full height (obviously transfering air from mid lift) increased the weight on the drive axle considerably, i experimented on one of our weighbridges confirming this works, the imposed weight on the drive axle going up from around 10 tons to around 15 at max weight, that's the difference between getting up that icy slippery slope or failing.
I can explain further whats going on there if anyone wants to know.

[DJ-DST]

The dump air button got you out of a lot of trouble when collecting milk in muddy farm yards!
We are currently having to go up a very steep road to get into the yard due to them building a new roundabout the way we normally come in, it’s rather interesting in the damp with 44t and a double decker LST!
Dump air helps a lot

[the-norseman]

CPC question.

I have a valid CPC, think I have 3 years left on it. I however dont drive for a living so I have no need to do the training every year.

When my CPC runs out, if I wanted to get it back do I have to just do 35 hours training or do I have to go do the theory/practical test again?

[Tisy]

the-norseman said:

CPC question.

I have a valid CPC, think I have 3 years left on it. I however dont drive for a living so I have no need to do the training every year.

When my CPC runs out, if I wanted to get it back do I have to just do 35 hours training or do I have to go do the theory/practical test again?

Assuming you already have a full truck licence and not just a provisional, only the CPC.

[the-norseman]

Tisy said:

Assuming you already have a full truck licence and not just a provisional, only the CPC.

Yeh I do, I just dont use it. So to regain CPC would I just need to do the 35 hours training even if CPC has lapsed?

[Smint]

If you're still involved in transport in some way could you get/cajole/persuade the company to pay for 5 individual days training (in work time) every now and again so it renews when the time comes...we do 1 day a year in-house.
It could be to their benefit as well as yours keeping you fully licenced to get out on the road at a moment's notice should the need arise.

[DJ-DST]

For the sake of a 40 odd quid, 7 hours a year course I’d keep it up to date.
A load of us at work use Atlas Training and do the split day. 3.5 hours on Saturday morning, and the same on Sunday. You hardly notice you’ve done it, and that 3.5 hours is less than that once you include a couple of tea breaks. It certainly beats sat for 7 hours straight

[the-norseman]

Smint said:

If you're still involved in transport in some way could you get/cajole/persuade the company to pay for 5 individual days training (in work time) every now and again so it renews when the time comes...we do 1 day a year in-house.
It could be to their benefit as well as yours keeping you fully licenced to get out on the road at a moment's notice should the need arise.

Network Rail aint going to pay for my CPC when I go no where near their HGV's

[Koyaanisqatsi]

In addition to the five normal Susies, what are the additional one or two sometimes seen on bulk carriers and tankers?

[s p a c e m a n]

One of them is probably a reversing camera, tippers are probably hydraulic hoses, other things can just be 24v for tail lifts ect.

I've got a pretty yellow one for my reversing camera, it's got to be a colour because idiots just mash them into random holes and blow st up

Edited by s p a c e m a n on Tuesday 7th October 08:27

[Smint]

Koyaanisqatsi said:

In addition to the five normal Susies, what are the additional one or two sometimes seen on bulk carriers and tankers?

As said reversing camera (when well sited are brilliant), Anderson lead for tank dehumidifier or other fittings ie tipping pump, some leave the hydraulic pipe connected all the time, and when a pressure tanker is physically discharging will usually be a large bore pipe always assuming the compressor is on the tractor unit.
Not sure what other pipes fluid tankers might have between tractor and trailer.

Spaceman's quite right about colour coded camera leads, or chumps plug the camera lead into the light fitting where 24v up the camera's bum doesn't do it any good.

Edited by Smint on Tuesday 7th October 09:53

[AGK]

Koyaanisqatsi said:

In addition to the five normal Susies, what are the additional one or two sometimes seen on bulk carriers and tankers?

Got an extra for reversing camera on my fuel tanker, brigade system with white plugs. Also two for the hydraulics for the pump. Some can stay connected all the time, others are in a position where they pull the rest of the susies out or make the lights flicker so they get disconnected between deliveries.

Some other tankers I’ve driven have had 3 hydraulics tho.

[Tisy]

s p a c e m a n said:

I've got a pretty yellow one for my reversing camera, it's got to be a colour because idiots just mash them into random holes and blow st up

When I was in the workshop drivers mashing ABS into EBS sockets and vice-versa was a thing.

Used to get VOR reports all the time for ABS/EBS "faults". Half of them when I'd investigate I would have no issue and so sign it off as done, only to have the driver come storming in next day ranting that it hadn't been fixed and I was useless . I'd climb up on the catwalk and instantly spot that the unit end of the EBS lead was still firmly connected to the storage socket...