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Saturday, April 19, 2014


10:30 am local CDT.  I am still at McDonald's, held here by the arrival of EMMANUEL and his magnificent 18 wheeler "Tractor" (Tractor = Driving portion of the SEMI TRUCK/TRAILER combination.)

Yesterday, I took pictures of SEMI Trucks, intent on including a SEMI story line in the blog.  I was missing a critical part of the story:  The TRUCK.

The Truck portion of a SEMI RIG is called a TRACTOR.

Lo and behold, while preparing to leave McDonald's for my morning walk, in drives EMMANUEL in his Tractor, in "BOBTAIL" configuration; i.e. the TRUCK driving without a TRAILER.

A Tractor driving down the roadway without a trailer is said to be "BOBTAIL".

There is a logical story line in the following images.  Taken two days apart, some sequences are out of place. 

Another couple hours effort, I could fix that, but I have already put three hours into this morning maybe next time.

The above image graphically shows the streamlined Tractor configuration.  In the recent 3 or 4 years, the trucking industry has made admirable efforts to streamline their rigs (rigs = Truck / Trailer combinations.)

Later images show tractors without streamlining that reduce air drag.  Reduced air drag lowers the effort of the motor to push the rig down the road.

Trailer Safety Bar contains reflectors at eye level of following vehicles and keeps following vehicles from driving UNDER the trailer if they are drafting (drafting = following closely the vehicle in front of you to coast along in their vacuum space.) 

As a WALKER walking within INCHES of passing Rigs all day every day, the greatest danger to my safety is vehicles DRAFTING rigs.  The drafting vehicles cannot see events in front of the rig...and have no time to take SAFE evasive action...they automatically swerve to the right - instead of left into oncoming traffic -.

Facing oncoming traffic, it is TO THE RIGHT WHERE I WALK.

A TRAILER SPOILER, installed along the side of the Trailer to deflect compressed air away from the trailer, creating reduced air resistance; i.e. use of less fuel AND control of air flow as it effects passing vehicles.

First noticed Trailer Spoilers 4 years ago on GTI (Gordon Trucking Inc.) trailers.  Most long haul Trailers are now equipped with side spoilers.

I have given much thought to spoiler installation benefits.  In my view, the spoilers should be placed with the leading edges of the two (one spoiler on each side of the trailer) spoilers as near together on the underside CENTER LINE as possible.  This allows the air flow to dissipate to the outside of the trailer rear undercarriage in a controlled uniform air flow.

Most spoilers have the leading edges to the outside of the centerline, allowing great volume of air to be trapped under the trailer in front of the trailer rear undercarriage, where significant compression resulting in blocked air flow requires more engine effort to overcome = uses more fuel. 

As with everything in my blogs, I am the first to recognize that I am master of nothing.  I am not an engineer.  I have no 4-year degree in anything (although I have attended advance learning class almost continuously)
and I like to remind some folks that I have hired and fired my share of PHDs along the way.  So, please take my observations and comments as being MINE alone.  A little Wiggle Room for freedoms taken would be appreciated.

Spoiler leading edge mounted to the outside of central air mass.

Spoiler ending far in front of rear trailer carriage

FEDEX Spoilers.  Question effectiveness of this installation.

Cattle Hauling Truck with side wall performing as a spoiler.

Trailer FIFTH WHEEL Dolly.

Fifth Wheel images follow below.

...and the LAND BRIDGE continues...many such LAND BRIDGE trains pass by daily.

The Trailer sits on top of the Truck (Tractor) Fifth Wheel.  The Trailer has a GUDGEON / PINTLE - or perhaps best to call the protrusion a PIN - which fits into the Fifth Wheel, effectively combining Tractor and Trailer into a RIG.

Self contained SOLAR POWERED Traffic Signal System mounted on a small, easy to move and cost effective.  Elimination of PEOPLE saves $$.  No FLAGGER needed here.

Six 90 WATT SOLAR PANELS power this system.  My self propelled cart SAM uses one 90 WATT SOLAR PANEL and one smaller 25 WATT SOLAR PANEL to help me cross America three times - sometimes pushing SAM - on foot.

Please say HELLO to EMMANUEL's Tractor in BOBTAIL configuration.

Please say HELLO to EMMANUEL and his relief driver ETHAN at their command positions of their Tractor.

Stainless Steel Steps to climb into the Tractor Cab.

Cab "SLEEPER", Saddle Fuel Tank, and Tool Box.

Exhaust Stack, another Saddle Fuel Tank.  Years ago - in 1951 - my family owned and operated TRI CITY FREIGHT which I learned a bit about trucking, having driven my first 18 Wheeler at age 9...and together with beloved little Brother, Jim, delivered our first fully loaded 60-foot trailer RIG of asphalt roofing - 27 bundles here...31 bundles there - at age 12.  So many stories...but this one is about Dad's loss of our new RIO Rig loaded with finished lumber when his Saddle Tank straps broke, tank fell under the back wheels where it exploded.  The entire RIG and lumber cargo was lost.  Dad was safe, but trying to save $$ by cutting every corner, the RIG and lumber were NOT insured.

At last, may I present the FIFTH WHEEL...the connector STEEL FORGING allowing Tractor and Trailer to become ONE...a RIG.

Mounted on the back framework of the Tractor, the Trailer FORGED PIN slips into the Fifth Wheel SLOT, where it is clamped securely and LOCKED in place with clamping devices built into the Fifth Wheel.

Yes, that is ALL that holds SEMI RIGS together.  I have never known nor heard of a  failure of this system.

Fifth Wheel Side View showing the handle which locks the Trailer PIN securely into the Fifth Wheel Slot.

Lots more considerations go into the design and manufacture of the Fifth Wheel / GUDGEON PIN connecting assembly.  One important feature is that the Truck Driver - who is ultimately responsible for the integrity and safety of his RIG and Cargo - MUST keep lots of GREASE lubrication on the mating surface of the Fifth Wheel and trailer GUDGEON PIN .

Name of EMMANUEL's Tractor.

These days, normal cargo is Gravel - Rock carried in Rear-Dump Trailers and Cow Manure Fertilizer.

007 Driver Dashboard.

ETHAN relaxing in the Truck "SLEEPER".  Some Sleepers are outfitted with all comfort features of home.

EMMANUEL and ETHAN wit their Tractor ready for inspection.

CAT (Catapillar) Diesel Engine.  This motor ha 6 cylinders, each cylinder producing 100 hp (horses = takes 100 horses to pull as hard as a single cylinder).  Normal RPM (Engine Revolutions per Minute) is 1,400, using 16 gears on a single shift lever to keep the engine at 1,400 rpm regardless of RIG speed over the road.

A second cooling FAN is available to draw additional air through the massive cooling radiator...essential to keep the motor cool when using all those horses to climb that long steep mountain hill.

When under heavy loading the 600 hp CAT Diesel Motor requires massive volume of ambient air.  Diesel Engines do not have an electrical component to fire off the fuel in the motor cylinders.  The fuel EXPLODES in the Cylinder chamber as the result of fuel VAPORS and AIR being compressed by the PISTON .

The large pipes carry the air from the BLOWER - the silver tank top left - to the motor cylinders.  Two blowers are used on this engine.

Detail of the air intake (top large pipe) and motor exhaust pipes.

Image of a Tractor with non contoured top surfaces.  A fully contoured surface most efficiently reduces air resistance as the RIG moves through.

A fully contoured surface leaves NO air turbulence.  A non contoured RIG surface can sometimes create such force as to blow me fully off the roadway berm as the RIG roars past.

I encounter hundreds of Rigs - sometimes every day - that I MUST mentally measure EACH and EVERY RIG as it approaches.  I must calculate the air turbulence it will hit me with BEFORE it reaches me; and do the same again and again for every approaching RIG.

Walking can become a rather scientific exercise to avoid being eliminated from the game.

A non-contoured air flow surface.  The Cab Roof Deflector is at best a unsatisfactory compromise.

These observations are necessary to correctly evaluate air force thrown at a walker in time to take adequate protective measures.

* * * * * * * * * *

This blog update may be a bit of an overkill.  I have been asked to share more technical detail.  With practice perhaps I will tend to get it right.

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