Dear John,
There are some other points that come to mind as well trucker
does not have any idea if container is loaded heavy one side or other or
aft & forward plus if load is well restrained as well.
This starts to undo Pandora's box.
Regards,
Graeme.
-----Original Message-----
From: Technical, operational and economic aspects of road freight
transportation [mailto:[log in to unmask]] On
Behalf Of John de Pont
Sent: Friday, 5 April 2013 08:12
To: [log in to unmask]
Subject: IFRTT Newsletter March 2013
IFRTT Newsletter March 2013
Greetings from the deep south,
It has become mandatory to begin these newsletters with a weather
report. Here we have had one of the driest summers on record. The
whole of the North Island is officially in a state of drought which is
causing significant issues for our farmers. The Minister of Finance has
claimed that the cost to the economy could exceed $2b. However, for the
rest of us it feels like it has been a great summer.
We have recently had an issue arise here with the stability of trucks
carrying high-cube ISO containers loaded to near maximum weights. As
many you may be aware New Zealand has a requirement that large heavy
vehicle must achieve a minimum level of rollover stability. The static
rollover threshold (SRT) must exceed 0.35g. Most of these container
trucks have been certified as meeting the rollover stability requirement
on the basis that the payload carried by the container is mixed freight
and thus that the centre of gravity of the payload is located at 40% of
the container height. In last few months several of these vehicles have
rolled over and it was found that the containers were loaded to the roof
with uniform density product. Thus the centre of gravity of the payload
was actually at 50% of the container height. The problem is compounded
because often the container is already packed and sealed when the truck
collects it and the driver does not know how the load is distributed
inside the container. Similarly enforcement officers cannot easily see
the load distribution.
Faced with the dilemma the government transport safety agency has taken
the position that as the container could be loaded to the roof with
uniform density product, this is the potential worst case load and the
certification for rollover stability should be done on this basis. The
issue that then arises is that most of the existing vehicles undertaking
this transport are tridem skeletal semitrailers which have great
difficulty in achieving the required level of rollover stability with
higher container weights. At the time of writing the way forward has
not been fully resolved.
This issue of the poor rollover stability of vehicles transporting
heavily loaded high-cube containers cannot be unique to New Zealand
although in other jurisdictions there is no minimum rollover stability
requirement and thus it is legal to operate vehicles with poor rollover
stability. If anyone has any information on the rollover rates of these
vehicles or on any counter-measures to improve their performance I would
be interested to hear from them.
Drive safely.
John de Pont
Vice President
Asia-Pacific
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