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Questions?
Comments? Something you'd like addressed here in the
Consurvatory?
Drop me a note:
gbraun@consurve.com
Going
far beyond the call of duty, doing more than is expected . . . . that is what EXCELLENCE is about.
It comes from continually striving, from maintaining only the highest
standards, from looking after small details, and going the extra mile.
EXCELLENCE simply means doing your very best in all your efforts, every day.
*
* * * * * *
The
Consurvatory
(Thoughts on current technical issues)
* * * * * * *
Safety in depots, pools and terminals is sometimes compromised due to
inattentiveness or rushing to finish a job.
Here are some of the more common examples of actions that unfortunately lead
to injury and sometimes death:
·
inadequate / inappropriate protective clothing for workers including shoes,
hard hats, gloves and protective glasses
·
difficulty being seen – lack of reflective vests
·
mechanic’s failure to chock chassis wheels when working underneath
·
precariously lifting container high off bolster while working on bolster /
pin / lock
·
using a box or crate to support a chassis / axle as opposed to proper jack
stands
·
not caging tires when airing, not airing safely with extension chucks,
standing in front of tire when airing, not having auto-pressure shutoff,
transporting and handling fully-inflated tires
·
failing to inspect rim lock rings, failing to read markings and match lock
rings & rim bases, using heavily corroded, damaged, dented, bent rims and
lock rings
·
not caging spring brakes – attempting to adjust spring break clamps – taking
spring brakes apart
·
smoking near combustibles
·
standing in water and welding or using electrical tools
·
crawling into stacks of chassis for inspection or repair – for any purpose
·
walking in between or behind mounted containers/chassis, especially when
there are tractors / hostlers operating backing into the chassis or adjacent
chassis
·
not reporting in and out at the office of the depot or pool – management
should know who is on the premises
1.
If they do not know you are out there, they will not come looking for you if
they don’t hear from you at the end of the day
·
not yielding to container handlers / forklifts / hostlers - you can see them
better than they are able to see you
·
walking underneath a container being repositioned or standing under a
container not properly supported by container stands
* * * * * * *
If you’re involved with operating container chassis, new Federal Regulations
(December 2008) covering chassis affect you in some way.
The
link to the new legislation is:
http://edocket.access.gpo.gov/2008/pdf/E8-29254.pdf
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* * * * * * *
The so-called "automatic tripping mechanism" on sliding axle
chassis does not in any way excuse the driver
from getting out of the cab and verifying that the slider index pins have
been properly engaged.
Likewise, the "stop blocks" welded onto the frame are for
positioning the slider only - they will not prevent the slider
from blowing out the back if the pins have not engaged. Slider pins
hold the slider securely - not stop blocks.
* * * * * * *
Loaded tank containers and dry van containers equipped with
"bladders" for carrying liquid cargo should not be transported
on conventional 23' slider chassis or heavy-duty tri-axle chassis with
straight frames.
Such containers require drop-frame chassis to keep the center of gravity low
for both safety and structural integrity.
* * * * * * *
Stacking chassis in the horizontal or vertical mode has become the rule in
ocean and rail terminals as space becomes premium.
Lifting, dropping, twisting and rotating chassis impose stresses for which
chassis may not have been designed.
Little is known of the short and long term consequences of such handling on
frame rails, bolsters, crossmembers and bumpers.
Until specific design criteria can be developed, we must rely on trial and
error and empirical data to make assumptions and hope for the best.
Careful and regular inspections of critical frame components are more important
than ever.
*
* * * * * * *
A wise man - Mr. Davidge Warfield - once counseled
me to think of "tires" as "sealed air
chambers."
Tire, tube, flap and rim work together to hold air; any one or more of these
links in the chain can cause a flat that is often blamed on the tire.
And by the way, the tire doesn't support the
chassis and the container . . . air does.
There's much talk these days about the re-introduction of 12 ply-rated tires
for container chassis. 12 ply-rated tires properly inflated to 75 to 80
psi support more load than is legal under the Federal Bridge Formula.
Worry less about ply rating and more about proper inflation.
*
* * * * * *
Given current arguments over the definition of "equipment
provider", let's remember that the driver too bears responsibility for
the condition of his chassis. Being paid on a trip basis is not an
excuse to skip basic chassis pre-trip inspection, especially tires, brakes,
and twist locks.
*
* * * * * *
Don't
cut corners when you have a chassis in the shop for repairs; before the
chassis goes back on the road,
do a thorough inspection and find and fix potential defects. Air the
tires. Adjust the brakes.
Check the lights. Perform an FMCSA (FHWA) inspection if within four
months of due date.
A preventive dollar spent now is worth quite a few remedial dollars later on.
* * * * * * *
Scheduled
preventive maintenance relies on inspection, diagnosis, and correction.
It is the opposite of "demand maintenance" wherein we wait until a component
or system breaks down before repairing.
Preventive maintenance can be likened to an annual visit to the doctor for a
checkup. The doctor does a "head-to-toe" inspection, and
advises the patient of remedial work to keep the patient healthy and free of
surprise and undesirable illness.
Contrast
annual checkup with waiting until illness or disease occurs, and then
visiting the doctor.
Preventive maintenance is not only prudent from a safety viewpoint;
it is also the low cost, most efficient way to keep equipment productive.
*
* * * * * *
Perhaps
the most important, yet least understood component of a container chassis is
the brake system.
There
are two separate and distinct brake systems at work on a chassis:
1.
Service brakes - these brakes bring the chassis to a stop at a red light,
stop sign, etc. They are activated when the driver steps on the brake pedal
of the tractor, or pulls down on the trailer brake lever usually located on
the right side of the steering wheel. These brakes apply through positive air
pressure, and are released when the air pressure is released.
(Never attempt to set a parking brake by pulling down the trailer hand
lever.)
2.
Emergency (spring) brakes - these brakes are for parking the vehicle. They
work by spring pressure, and not the application of air. In fact, they work
in the absence of air pressure - when all air
pressure is lost in the chamber. The driver can apply the chassis emergency
spring brakes by pulling the red knob on his tractor. (Pulling the yellow
knob on the tractor will activate BOTH the tractor and chassis
emergency spring brakes.)
Slack
adjustment for both service brake and emergency brakes is the same. On
manual slack adjusters, 2" is the typical maximum before brake
adjustment is required. If adjustment is off for the service brakes, it
will be off for the emergency brakes, and vice versa. Use
service brake pedal to apply air pressure for adjusting, not spring brake.
The
fact that the service brake system works is not a guarantee that the
emergency brake system works, and vice versa.
Be sure to check BOTH systems each time the chassis goes on the road.
* * * * * * *
Wheel
bearing adjustment and lubrication are often overlooked. Poor wheel
bearing adjustment can translate into
shortened bearing life as well as affecting the spindle, wheel, seals, brake
components and tires. The National Transportation Safety Board
estimates 750 to 1050 wheel separations each year with improper wheel bearing
maintenance as a potential cause.
Wheel
bearing damage may have already begun if you notice:
Discolored
or burnt hubcap sight glass (on oil bearing seals)
Low lube levels
Lube leakage (check both outboard and inboard)
Abnormal tire wear
Smoking or hot-to-the-touch hubcaps
Wheel vibration
Wheel wobble
Wheel noise
Decreased braking power
Pulling to one side or the other
Wheel lock-up
Bearing
and axle manufacturers recommend that wheel bearings be inspected / service /
lubricated annually
or when a brake job is performed (unless there is reason as described to
inspect earlier.)
Annual bearing service on chassis in typical local service is probably not
necessary,
but bearing service at least every three-to-five years is reasonable.
If you are in doubt about service intervals, contact the chassis manufacturer
or axle manufacturer; it is better to err on the safe side.
This list of when to inspect / service wheel bearings can for convenience be
extended to tire changes, end-cap removal, maintenance or replacement of
S-cams or bushings, checking for abnormal tire wear and seal leakage.
Service or replace the wheel bearings if you observe:
Dry
or ‘caked’ lube
Metal particles in hub cap or bearings
Heat discoloration
Visual wear
Dents on bearing cage assembly
Noise when rotating wheel
Moisture
Uneven spindle wear
Loss of adjusting nut torque
Worn or damaged seals
Mounted wheel end-play
Chassis wheels should be pulled when there is visible reason to do so,
such as noting separated brake shoes,
a cracked drum, grease on a drum from a bad seal, ineffective brake action,
etc.
Otherwise, drums should be inspected and bearings re-packed and re-adjusted
when part of a brake or seal job.
Adjusting wheel bearings is properly done with an endplay gauge at the time
of major wheelwork.
The recommended process can vary from one axle / bearing manufacturer to
another.
If you are in doubt about the correct process for your chassis, please check
with an expert.
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