Got the 'Bends'?

[Andrew21]

No, this thread is not about diving. It is about articulated buses. I have been able, over time, to take some photos of some artics at or close to maximum turning capacity. For those who have not driven artics before, many have what is called a "Jacknife Brake", which engages like a park brake if pressure on the turntable reaches a certain point when turning. On the older artics, the sensor (so I've been told) is located outside the bus above the concertina on the roof and looks like a rod between the "tractor" unit and the centre of the turntable. To override this brake, the driver must hold down the "jackknife" button to release the brake until such time as the bus is no longer jackknifed. Those who have travelled on a 142 bus to Greenbank RSL may have witnessed this in action as the u-turn there requires use of the jackknife brake override. I hope these photos will be of interest to you all.

Volgren bodied Volvo B10M artic #982


Jackknife warning light located on the dash.






Custom Coaches bodied MAN NG313 artic #1602


Jackknife warning light located on the dash

[Hornibrook]

Nice pictures and thanks for the info! I have only ever been on (3) BT articulated buses (believe it or not), plus (1) HBL Fuji.

[Sir Joh]

Switches are in the turntable, not the bellows

[AEC Decker]

Interesting post , where is the jackknife button on the Volvo ?.
Remove the yellow bits on G1602 and you could pass it off as a NSW STA bus.
The UTA/STA Mercedes O305G don't have now or didn't have a jackknife brake or override button when AEC Decker was trained on them in 1984.

[Volvo B12BLEA]

Interesting post , where is the jackknife button on the Volvo ?.

2nd pic to the right of the dials you will see a red button with what looks like a bent rectangle on it.

Andrew21...good pics. The only way to take pics of an Artic...having a bend in the middle. They look plain & boring in a straight line.

[mrobsessed]

The Adelaide Volvo artics have the jackknife button near the gear buttons. Mercs and Renaults have a pin that locks the two portions of the turntable together to prevent damage to either portion of the bus or to the turntable. The pin needs to be released by a mechanic. Good fun when a linc gets locked up in an inconvenient place - as they do!

[Andrew21]

Interesting post , where is the jackknife button on the Volvo ?.

It's located on the panel of switches normally to the left of the main dash. The exact location varies from bus to bus. On the MAN's, it's located on the panel of switches to the right of the main dash.

[Michael]

Say you was to plant that rear-powered MAN in the wet, would the trailer push the bus sideways and jackknife itself further? Also, is the trailer able to rotate to the bus or just up/down/left/right?

Another one, who makes the concertinas and what are they made of?

Also, why are the 30km/h and 50km/h numbers printed in red on the MAN speedo?

Stanny M

[STA 1440]

I believe there is a really complex system of hydraulics that prevents a powered trailer pushing the front section sideways.

As for the two halves "rotating", I gather youre asking if both halves can twist relative to each other? If so, I think they are designd to 'twist" a little bit, so as to cope with awkward angles and road conditions (i.e: a sharp corner at the base of a hill, or when one wheel goes up onto a curb).

You may have to ask a real expert, as I've only been told this by my grandfather, who was a mechanic at TransAdelaide.

I've heard that our Volvo artics here in Adelaide had to get their trailers lifted up by a crane and moved over in order to unlock the brake, is this true?

[VH-NJF]

As for the two halves "rotating", I gather youre asking if both halves can twist relative to each other? If so, I think they are designd to 'twist" a little bit, so as to cope with awkward angles and road conditions (i.e: a sharp corner at the base of a hill, or when one wheel goes up onto a curb).

You may have to ask a real expert, as I've only been told this by my grandfather, who was a mechanic at TransAdelaide.

I've heard that our Volvo artics here in Adelaide had to get their trailers lifted up by a crane and moved over in order to unlock the brake, is this true?

6 degrees either direction is maximum twist.

And yes... we've had that kind of thing with our artics too. where the brake wont release.

I had to skip the trailer of 379 across the workshop floor to get it out of the paint booth one day last year.

[PAQ12]

Nice pics and good description, although i'm somewhat sceptical of the detail of button locations as we never know who could be looking at 'borrowing' one of these vehicles without authorisation

where is the jackknife button on the Volvo ?.

2nd pic to the right of the dials you will see a red button with what looks like a bent rectangle on it.

Thats not a button, thats a warning light to indicate the bus has jack-knifed!

I believe 980 is the worst for jack-knifing (so I was told by several G and ex G drivers).

There use to be another artic, now long gone and I believe it was one of the demonstrator units back in the 80's possibly (can't remember which one), that it was based out of Light St depot, and was the only artic forbidden to use the Montpellier Rd roundabout just down the road from the depot (intersection of Wickham/Ann/Breakfest Creek/Montpellier Rds) due to jack-knifing everytime.

[Sir Joh]

Sir Joh wishes to enquire about the location of the 2 buses posed for photos.

Joh
Peanut Farmer

[adx666]

I remember a few years back a Renault artic on route 185 jack-knifed on Wellington st in Perth blocking the west bound lanes of Wellington st. I think it was 696?

[Andrew21]

Sir Joh wishes to enquire about the location of the 2 buses posed for photos.

Joh
Peanut Farmer

Only when Sir Joh publically reveals his REAL identity and doesn't have his website link to the stupid LNP website.

[Hornibrook]

1 would be somewhere near Greenbank or Sunnybank Hills, i presume, the other in Larapinta depot?

[BTBOGAN]

The location would have to be the Big W loading bay at sunnybank hills for 1602 pic.....
And the pic of the Old VOLVO is in the turn around bay just behind the inbound 140 CXP Stop at Honeysuckle way.. So cnr of Beaudesert rd & nottingham Rds Calamvale...

Do i get a prize for Guessing Correctly???????? I willl Accept a Chocolate Bunny.. ( considering it is easter after all )

[renaultartic]

Great topic. I've never actually locked one up however when driving Perths Renault artics, sometimes I've had it at the point when the alarms sounds where it gives me the time to straighten up. I witnessed a Merc O.305G getting stuck in a rail station carpark once. He ended up getting the bus out by 'forcing' it out back and forth in the bent position. He was very lucky not to do damage if it hadn't already.

Leigh.

[d_train]

awesome pics , i didnt know they had warning lights , in wa the horn blows as the warning .. (it did one one i nearly locked up when i started)

[Maladjusted]

Good Pics of the Artics Andrew I'll never forget the view I saw of an Artic going down the (M1 now) Freeway and fishtailing about ten feet (5 each way) in the wet.
Normally on a Volvo the alarm(same as the Sonalert) sounds first then if you ignore the alarm and hook it around further the JK brake hits home.
But... if the JK brake comes on during forward driving then either the limit switches need adjusting or the steering box needs the limits reset on it.
The JK brake shouldn't come on unless reversing. Can be a pain but the earlier artics didn't have a reset or release button.

The turntable on the bum of the PM does not allow for "twist" as such, this would only be gained in the chassis of both front a& rear units. In fact this may account for the Fuji's to have the chassis on the trailer beefed up and cracks repaired (maybe Brisbane Rds though)
I had to replace a ballrace turntable once, not much change out of $8k thru Volvo, similar one bought locally $1k but the Volvo fitted straight in no drilling or anything bus in and out the same day. Also doing a trailer alignment by joining the dots on the floor covering!

The bellows are 2 layers with fabric stiched together with steel edging on the outer and inner edges much the same as a piano accordion.
When the BCC 375-380 ones were delivered they had to come from Belgium. I heard recently they were still around the $15k and about 6-10 weeks delivery.