On the Road Again

[DMiller]

Brakes on the old Eucs were next to useless most of the time, pit monkeys were BAD for doing similar and the side scars where they used the haul road wall as a Friction brake were obvious.

 

[kshansen]

Been there done that with 773B models and the first traction controls that I ever worked on. Our roads were steeper, the corners were a lot sharper and the driver's treated the trucks like four wheelers on a dirt racing track. The material was glacial till and this is western Washington State with the associated amount of wet. You would see trucks sliding broad side most of the way into the pit and coming to a stop under the wheel loader buckets without making a 3 point. Tire costs were immense.

I recall working on a 773B something about not shifting as I recall probably the switch at the transmission that moves in sequence with the one in cab to keep things in sync. Anyhow running empty down a little used haul road flat out to make sure it had all the gears. Then decided to hit the brakes like you would on an old R-35 Euclid! Yikes glad the road was nice and wide so I had time to straighten it out!

 

[kshansen]

Brakes on the old Eucs were next to useless most of the time, pit monkeys were BAD for doing similar and the side scars where they used the haul road wall as a Friction brake were obvious.

The old R-35's were not too bad despite what I just wrote but you had to have everything up to snuff and adjusted just right. Some time the parking brake would actually hold on grade, if it had a good drum on the back the CLBT5860 Allison and the cable was not rusty and stiff.

Although on a couple of the R-35-B Terex trucks which were basically Euclids built in Brazil we had added Maxi-cans to the front brakes and installed air chambers to work the parking brake on the transmission. Even with all that still had to get things set up right to pass MSHA brake tests for parking brakes.

 

[DMiller]

Too new for what I worked LOL!!
Newest was a R24 and a couple R 25s
Most of them were R10s 15s a few bigger 35s and a couple oddball Terex when they merged

 

[Mark250]

Talking about traction
Here is a sequence of events from a Cat 785D haul truck VTMS report working in slippery conditions
this is from early model machines and the ECM strategy was not quite right
it is very rare for this to happen to current machines
Operator applies service brakes

Rear wheels lock up and transmission down shifts to second gear



operator releases brake rear wheels regain traction machine is still in second gear
engine spped increases to a level three event of over 3000 RPM

 

[Mark250]

The result
one toasted 3500 series engine

 

[Nige]

We had loads of those in 1HL-prefix 793B & 4AR-prefix 793C's back about 20 years ago, but the ones we had were on dry roads and were a result of a "hole" in the EPTC-II software that would force a downshift from 5th or 6th to 1st if the truck lost Transmission Output Speed (TOS) signal due to a connector or wiiring harness fault. The signal had to come back again at or close to zero, the control (which had been holding in gear as a result of the loss of TOS signal) would think the signbal was genuine and call for a transmission downshift. The fix was a software that used the engine speed sensor to ratify the TOS signal. I recall working over a weekend in our CRC with a guy from Cat TBU to re-chip (no flashing in those days) probably close to 200 EPTC-II controls with the chip containing the updated software. I well remember the Diagnostic Code they used to throw just before everything went t!ts-up - MID 27 CID 718 FMI 11.

Edit: just looked back through my files and there were actually 23 engines that we knew about. There may have been others in the same time period that were put down to different circumstances.

 

[Mark250]

We still had those issues with the TOS on the early D series as well. I just pulled the above case out of my files as it was a loss of traction issue

 

[Truck Shop]

I love hearing about engineering failures, engines disintegrating, crap coming apart because of silly a$$ computer controlled systems. We get what we ask for.

 

[DMiller]

Ouch and Yes we do generally ask for it

 

[Birken Vogt]

Seems that the average mechanic could have thought this through better than the programmer that designed it. "What happens when the VSS goes bad?" The question was probably never even asked let alone attempted to answer before released to the field. Just ship it and let warranty work the kinks out. Never mind the customer.

 

[Truck Shop]

You hit that one on the head VB.

 

[Truck Shop]

The bosses next move is to install automatic chains on 75% of the tractors, we already have five that have it because the drivers are 65 plus years old and can't throw chains, what about the trailer?
On those rigs with auto chains those same rigs have disc brakes, in order to inspect the brake pads you have to remove the drive wheels each time because you can't see the pads with the auto chains
in the way, you can barely reach the fill plugs. I asked The boss when are you going to buy the shop a 200 ton post lift so we can lift truck and trailer together--Crickets.

People and there automated crap. Sorry for the hi jack Nige.

I left out the Freezer plant that went robotic loading-in the first four months damn near 30% of the loads were wrong, seems the robot couldn't get the bin/shelf location right. Ordered onion rings
and got Hog rotten potato's instead.

 

[Tugger2]

Lets get the smart humans back in the equation !

 

[Nige]

Lets get the smart humans back in the equation !

And if it wasn’t for some of the smart humans kicking around the software developers would be in even deeper sh1t than they would be otherwise.....!!

 

[kshansen]

Seems that the average mechanic could have thought this through better than the programmer that designed it. "What happens when the VSS goes bad?" The question was probably never even asked let alone attempted to answer before released to the field. Just ship it and let warranty work the kinks out. Never mind the customer.

Just watched a show on air plane disasters last night. In this one the dash indicators for the pilot and co-pilot were connected to separate inertia sensors that gave read outs to whether the plane was climbing or diving.

If they did not agree there was a indicator that popped up to alert the pilots to the fact that there was a discrepancy. This was suppose to tell the pilots to check a different gauge to determine which was the correct reading.

Well if the pilots did not respond within something like four seconds the computer would switch to a "de-clutter" mode to simplify the screen the pilots had to deal with. Problem is one of the indications that were removed from the screens was the warning that the two pitch indicators were not agreeing with each other!

As this was a night flight the pilots had no visual indication of the horizon to go by and the fact they were in a fast nosedive they did not have any sense of gravity to go by and they hit the ground at about 600 mph actually slightly inverted. Needless to say no survivors. Good thing, if there can be in this situation, is this was a freight plane with not passengers so only the two pilots killed.

I can only hope that who ever designed that soft-ware was made aware of this screw up!

 

[kenh]

The co-pilot realized there was a problem, capt. ignored him. Capts. gyro went flooly)
They never looked at the 3rd indicator, which would have shown the copilot;s was correct.
A glance at the altimeter and airspeed would have con rimed they were diving and and gaining speed.

 

[Truck Shop]

It's why I prefer to walk or drive, propellers and such can go along ways into the ground. Nothing there I wanted to see anyway.

 

[Nige]

My late father (ex-RAF WWII) always opined - "Only fools & birds fly, and even birds don't fly at night."

 

[John C.]

I'm not fond of modes of travel where the failure mode of the machine means death of the crew and passengers. I can pull my car or motor cycle to the side of the road if the engine quits running. Doesn't work that way for a plane in the air or a ship on the ocean.