| Author |
Message |
ChuckMC9 (Chucks)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 12:28 am: | |
You guys have cautioned us all time and again about downgrades - here's one that got away.
...Witnesses said the RV, a converted bus that was towing a car, came down the hill towards the Big Bend Corner (a short drive past the Columbia Icefield) and collided with the two oncoming cars, both of which were severely damaged by the bigger vehicle...
http://www.jasperbooster.com/story.php?id=183719 |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 12:42 am: | |
Yeah well.... *&$^% happens. |
Mike (Busone)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 1:15 am: | |
I wonder what kind of bus it was? |
bruce king
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 2:19 am: | |
I was just up there last week; the hills aren't all that steep. Maybe something as simple as the driver dozing off.
There are steep hills, but the road, at least the western approach to jasper, isn't that bad. |
Sojourner (Jjimage)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 10:33 am: | |
Or perhaps bus or RV driver was going too fast before going into down hill Grade while applying brakes.
As most large heavy downhill runaway vehicle are due to ALREADY red hot expanded drum & cooking shoes….No Brakes is result.
http://www.edmontonsun.com/News/Canada/2005/09/08/1207050-sun.html
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/16163911.cfm
Maybe we (including me) can learn from this horrible mishap to do double safety check our coach before trip. Hopefully reports of “how and or why” will be available later
Having equips with ( even if it new) adjusted brake shoes & good drums, whenever I drive thorough new areas, especially approaching downhill drive is to heed the “steep hill” sign and drive at controlling speed incase whatever happen if braking system to fail. With my MCI-8 w/na8-71 automatic trans & tow, I slow to 15mph in lower gear then let up brake until 25 mph during 4% down grade. I don’t have Jake or retarder but even if it did I would not go over 35 or otherwise slower. So I try to have full control of the missile in case something goes wrong.
Many trucks drive passes me …whoosh….downhill are gambling his and people’s life. I don’t think any trucker who had a runaway experience will pass me (downhill) driving my bus. Perhaps still slower than I!
FWIW
Sojourn for Christ, Jerry |
niles steckbauer (Niles500)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 2:04 pm: | |
*** speculation only ***
there is a lot of game on that roadway, as it bisects the park, and the driver may have been avoiding sudden animal(s) darting across the road - it also frequently drizzles and sleets along that stretch, and though there's no sign of it in the pic, it may have already dried up during the time it took to get to the scene - JMHO - Niles |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 3:28 pm: | |
Man oh man that's an awful story.
While we're on the topic of brake safety, let's also not forget that a braking system on a toad/trailer of any weight is a good idea.
I'm with 'ya Sojourner. Every time I go down a grade I remember the old trucker's adage: you can go too slow down a grade a thousand times... but go too fast just once.
Words to live by...
bb |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 3:43 pm: | |
100% right Jerry. You remember a runaway for the rest your life. |
Gary Stadler (Boogiethecat)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 6:28 pm: | |
So since someone passed the subject of brakes on a toad by here, I have a question about that.
I just built a 6000 pound trailer that I tow behind my bus. Initially I put hydraulic surge (disk) brakes on it because they make a lot of sense considering various vehicles I'll be towing it with.
But, what doesn't make sense is:
What do you do with surge breaks when coming down a long grade? It seems to me that if you allow them to function while the bus engine is holding you back by using a retarder, that the surge brakes will be on all the time and likely burn up.
So far that was my experience... on the first grade I came down, they got the spindles so hot that pressure built up in the bearings to the point that two of the grease caps actually blew off!
So for the remainder of the 1000 mile trip I disabled them, and nothing further went wrong.
I can see that if I had electric brakes this wouldn't be a problem...if I had them set only to go on when I press the brake pedal... but again, if I were to rely on the gravity sensor in an electric controller, I can't see how the brakes wouldn't burn up coming down a long grade.
How do all of you deal with this? (or am I nuts?) |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 7:20 pm: | |
Gary, could something have been wrong? If the surge actuates, it should place the hitch in tension and release the brakes cuz the hitch would extend, disengaging the brakes.
Am I missing something here? |
Gary Stadler (Boogiethecat)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 7:55 pm: | |
Um, me thinks so Marc.... go downhill slowly, weight of trailer pushes against bus which pushes on master cylinder of surge brake, applying pressure to brake pads. A balance occurs making the brake drag equal to the downhill weight vector of the trailer.
What happens is that the brakes get applied mildly all the time, keeping the balance of brake action vs actually pushing on hitch. The bus sees little of the trailer weight because the brake pads are being squeezed the whole time, getting hot as they go.
At least that's what it seems is happening.
Even coming down a short grade (like 1/2 mile of 6%) the hubs get hotter than hell.... |
Sojourner (Jjimage)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 9:16 pm: | |
Weight x percent grade = lbs of force downhill.
6000 x 6% = 360 lbs of force (push).
Mean if master cylinder is straight or direct ratio w/1" piston connects to all drum equips 1" wheel's cylinders then between each shoe & cylinder force is 360 lbs. However much higher force leverage points toward anchor pin.
Disc brake has larger caliper pistons which mean greater force of clamping = higher temp but disc can take more temp without lowering brake pedal, Mean higher speed fade resistant then drum (expand while heating = larger dia) type.
Am I right? Correct me if I am wrong.
FWIW
Sojourn for Christ, Jerry |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 10:56 pm: | |
Gary, why would the surge brakes do more braking than what it takes to hold the trailer on the grade?
If the trailer braking is only holding the trailer, then the braking only has to be good enough to dissipate the heat from the trailer braking.
Are you saying that the trailer brakes were doing more than holding the trailer? Or that the trailer brakes weren't adequate to hold the trailer?
I would be very interested to know which.
Tom Caffrey PD4106-2576
Suncatcher |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 11:03 pm: | |
It sounds like he's saying that the trailer brakes are dragging
on long declines when they shouldn't be on at all. The Bus's
engine brakes keep the bus and trailer in check, but the trailer's
surge mechanism is keeping the brakes activated needlessly.
The only recourse would be to change it all out to electrically
controlled brakes, and have an override at the driver's disposal. |
David Hartley (Drdave)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 15, 2005 - 11:38 pm: | |
Add a switch and a backing solenoid to the trailer brake line. The switch would disable the trailer hydaulics and could be toggled on and off to apply trailer brakes as needed on demand.
Backing solenoids are almost a necessity on surge braked trailers and they are usually hooked to your backup light circuit.
Maybe a toggle to turn on the backup lights on demand would be the quick solution if you already have the backing solenoid installed and working.
Either that or increase the tongue spring tension but that migh be a problem.
I have seen an Electric over Hydraulic pump/controller on some big boat trailers and goosneck trailers. Uses a standard electronic brake controller and translates to hydraulic right on the trailer. |
Gary Stadler (Boogiethecat)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 16, 2005 - 1:19 am: | |
That's how I disabled them on the trip, stuck a switch on the dash that turned on the backing solenoid.
Tom, the brakes are only holding back the trailer, but as john said, the constant dragging on long hills is what's making them get damned hot. Hotter than I think they should. I was just curious if that's a normal thing for surge brakes or maybe surge brakes are only good for city driving, not long hauls with long grades...??? |
Gary LaBombard (Garylee)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 16, 2005 - 5:52 am: | |
Chuck,
Please contact me so I can request permission to use information you have posted in an article I am writing. I tried to use your BNO bb contact address but got returned mail.
Gary |
Russ Barnes (Neoruss)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 16, 2005 - 9:11 am: | |
I have spent over 35 years in the high volume, but light GVW trailerable boat industry; designing, manufacturing and marketing. We've used surge brakes as long as I can remember and they work well on these trailers (up to 6k)and they sell them for heavier units, but I have no first had experiences.
When we used drum brakes we just put the truck in reverse and backed up because the brake manufacturer shaped and sized the shoes so they don't work efficiently in that direction, therefore a slight drag that a Detroit V8 could easily overcome. When we changed to discs we had to install solenoid valves because discs work as well in either direction. To avoid the nusiance of toggles or other wiring we simply went to 5-way trailer harness connectors and use the back-up lights to activate the solenoids. |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 16, 2005 - 9:58 am: | |
Gary, I use electric brake controllers on several vehicles for towing our equipment and they are not gravity activated. In other words they do not have the swinging pendulum that was prevalent in older design actuators. The latest design actuators can be mounted in any plane, and mine are all at approximately 45 degrees to match the slope of the lower dash. I really do not know how they work other than they work great. I haul a 12,000 pound excavator and trailer with a ¾ ton dodge 4x4 with no problems on the mountains in this area. Yes, I know they are not like the Rockies, but a lot of 6% grades are common. If you need to switch to electric brakes, I highly recommend these units.
Richard |