Thread: Bridge weight limit sign confusion..

@
Micky Duck

No ford, the stream is narrow (maybe 4meters) and deep.
But heh, what can possibly go wrong
Thanks everyone!

My neighbour had to replace a bridge recently. This is the old one, that had a wooden overlay, and that I was driving my tractor over right up until the replacement. Bloody scary looking at those RSJ’s now...


Here’s the new one...


I’ve got to ram a few posts in and tidy up...

Originally Posted by ishoot10s

My neighbour had to replace a bridge recently. This is the old one, that had a wooden overlay, and that I was driving my tractor over right up until the replacement. Bloody scary looking at those RSJ’s now...
Attachment 130020

Here’s the new one...
Attachment 130021

I’ve got to ram a few posts in and tidy up...
Attachment 130022

A tad over-engineered compared to the old one ... which in fairness did well until it got replaced. But the new bridge will outlast us all by a wide margin.

Looks very professional, do I need a new mortgage for something like this?

Stable flood proof abutments are critical. If not a log pig then concrete sandbags locked like bricklaying and reinforced with vertical steel bars rammed right through into the base foundation.

They rammed 4 x 7m poles that were 450 SED, into each footing, then capped them with a concrete buttress before dropping the two bridge halves on top. The rocks are window dressing. This method was cost effective compared to a culvert system that disturbed the stream bed and would have cost megabucks in enviro reports and impact studies etc.

You can see the poles under the cap here, Long galve bolts through the cap and poles...

With the Class 1. I thought Class one driving license was referring to "normal car" class which I believe is up to about 4.5 ton. so 30% under class one would be about 3.1 tons?

Originally Posted by timattalon

With the Class 1. I thought Class one driving license was referring to "normal car" class which I believe is up to about 4.5 ton. so 30% under class one would be about 3.1 tons?

They snuck class 1 licenses up to 6T for a full license, but the bridge is not based on driver license class but road/structure class.

https://www.nzta.govt.nz/vehicles/ve...ions-and-mass/

Originally Posted by gadgetman

They snuck class 1 licenses up to 6T for a full license, but the bridge is not based on driver license class but road/structure class.

I knew they did something like that about 2009 in preparation for the big campervans they were expecting for the Rugby world cup. I was under the [mistaken] impression that they had put it back down to 4.5T . As my wee Suzuki Vitara 5 door (1.6l) wont manage to tow a trailer that would put me close to going over 4.5T limit I have never worried about how close I was getting to it...

Originally Posted by timattalon

I knew they did something like that about 2009 in preparation for the big campervans they were expecting for the Rugby world cup. I was under the [mistaken] impression that they had put it back down to 4.5T . As my wee Suzuki Vitara 5 door (1.6l) wont manage to tow a trailer that would put me close to going over 4.5T limit I have never worried about how close I was getting to it...

For light vehicles they don't count the combined weight anyway. Each is taken on it's own, so you'd have to get the zuk with that weight on it's wheels.

Originally Posted by diana2

Hi, can anyone please explain a bridge sign seen on a private property just of the main road which has written on it:

Heavy vehicle bridge limits
Axles Class 1
Gross 30% Class 1
Speed 10km/h

Question is, what is exactly the weight for class 1 ??
Does this sign mean the bridge is on it's last legs and using it with a small truck is plain crazy?
Who measures this? and do these signs change when the bridge deteriorates?

I googled many opinions and everyone has got a different interpretation..
The worst comes from gv nz with many little round dots and letters inside that doesn't explain anything.
For example, can the bridge been used by a truck carrying a 20ft empty shipping container? (they usually have two rear axles, I think)
can the bridge been used by a normal sized tractor and trailer or motor home?...

Bring this conondrum one up next time someone says they're "just a truck driver".

Originally Posted by gadgetman

For light vehicles they don't count the combined weight anyway. Each is taken on it's own, so you'd have to get the zuk with that weight on it's wheels.

My Zuk can get VERY heavy loads moving quite nicely. The bit that worries me is slowing that weight down for a corner at which point the Zuk is there for decoration and just along for the ride....I have used it to move a trailer with 2cube of concrete rubble around the section. But I would not lik eto try it on the road....I like my zuk too much to try burn it.