The ConSurvatory – an Industry blog

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"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".....George Braun

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New Federal Regulations (FMCSA) for container chassis

If you're an IEP, is your systematic inspection / maintenance program in effect? If you're a Motor Carrier, are you prepared to submit daily reports and perform professional pre-trip inspections? When (not "if") audited, will you pass the test?

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Common examples of actions that lead to injury and death

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

Automatic tripping mechanism

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.

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Loaded tank containers and dry van containers with bladders

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.

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Stacking chassis in the horizontal or vertical mode

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.

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Proper inflation of tires

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.

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Driver responsibility for chassis pre-trip inspection

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.

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Fix potential defects

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.

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Scheduled preventive maintenance

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.

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Brake Systems on Chassis

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.

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Wheel bearing adjustment and lubrication

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.

Wheel Bearings service

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.