| Author |
Message |
duanekaler
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 19, 2006 - 8:38 pm: | |
After a year of research and kicking around ideas I am looking at buying my first bus to convert, an MCI 7. My question to all you pros is, if the interior has already been stripped including the inside metal paneling and side windows, will this bus be structurally OK to drive home? Thanks for any help with this. |
Doug Wotring
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 19, 2006 - 8:50 pm: | |
Not a structural engineer.....but I would say no.
if windows were in it I would say go for it.
But without windoes there is way too much stucture missing.
Low Boy would work |
Ross Carlisle (Rrc62)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 19, 2006 - 8:51 pm: | |
Some will tell you that driving without the interior panels will break the bus in half, but people do it and buses are not breaking. Technically, the interior panels are considered structural. Armed with that info, it's really your call as to whether you drive it or not. I drove mine without the panels, but I had already re-skinned the window area, which added structural integrity where there was previously just open space. |
Ross Carlisle (Rrc62)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 19, 2006 - 8:55 pm: | |
The windows add no structural integrity. Windows are not "structure", they just fill the holes. |
Ed Jewett (Kristinsgrandpa)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 19, 2006 - 9:04 pm: | |
Without the 8000 to 10,000lbs. of passengers and luggage it was designed to haul and the 2000 to 4000lbs. stripped from the interior, you should have a pretty light coach.
Distance and road condition is a consideration.
Ed. |
Gary Stadler (Boogiethecat)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 19, 2006 - 10:04 pm: | |
Gawsh I love my Crown! Real frame Rails!
Wheeeeee |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 19, 2006 - 10:11 pm: | |
The individual at MCI (Kissimmee, Fl) I talked to, claimed
the window frames, and the glass and frame, were all considered
to be part of the engineered structural design.... along with
the luggage racks, seat rails, seats, etc...
He explained (in so many words), that to keep the bus as
light as possible, yet have the strength to support all the
weight (and afford the flexing that takes place), every item
in the bus's design, contributed to it's overall strength...
I do know, that after I removed the racks and seats and rails
in my MC9, the bus door would bind on it's frame if the bus
wasn't level (when the air was depleted). It was fine, prior to that.
I left the chassis window frames in, and covered over them..
(John MC9's 11 ton boat anchor)
If I had to do it again, I'd either remove 'em and reinforce the
opening, or run the sheet metal to the bottom edge of the frame.
If it were me, I'd pass on a totally stripped bus.... |
Doug Wotring
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 19, 2006 - 10:35 pm: | |
Windows and window frames are most certainly structural on any Monocoque designed bus
take a tin can and cut a bunch of holes in it........it loses strength and rigidity
driving that MC& without interior metal panels and windows will in deed kill that bus.
in the same idea....taking the rivets off the back of a GM bus will cause the entire engine to fall out...as it is supported by the firewall and the roof |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 1:43 am: | |
Doug, just to be clear on what the "window frames" are: on your typical "punched opening" coaches (MCI, GMC, Eagle, etc.), the steel framing around the window openings are structural supports for a bus. The actual glazing and sashes (window frames) are not, since they are not structurally attached to the skin of the bus and the other framing members. If they were held in tension that way, they'd never be operable (for those units that are).
On most of these busses, for emergency egress the entire window can be pushed open, since they're hinged from the top. If the window was being used by the structure of the bus, you wouldn't be able to do this. Plus, the actual glazing could crack when put in compression (from bumps, lateral movements), if the frames and their glazing were being used for structural support.
Skinning a bus and riviting new steel or aluminum into the framing around the old windows provides much more shear support than the old window units ever did. And even more so, if the old openings are infilled with more sturctural members.
Same concept: Sheathing on a house with the wood framing around the windows (jambs, sills, trimmers, etc.) You can never count the actual windows as structural support/ shear resistance. In fact, their resultant "holes" are just that... and compromise the integrity of the structure and its shear resistance.
Brian Brown
(not an engineer, but an architect)
and a BusNut |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 1:57 am: | |
Brian has it right!
Another aspect is the increase in structural strength occasioned by raising the roof (if properly done)
BTW, I dont' remember anyone posting that a bus will break in half if the interior shear plates were removed.
If stripped, just a ferry trip and no off road adventures, just inspect for cracks after you're home. |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 2:29 am: | |
Marc, as you probably know, the biggest bugaboo in roof raises is the gotcha of slenderness ratio. In statics [where we ignore dynamic loads and "shell factors" as indeterminants for simple(r) calculations], every structural member acts as a beam. Double a beam's span and you have to increase its depth by a factor of four.
As a simple exercise, one can take a piece of dried spaghetti and play around with span/loading "failure" analysis to get the gist of what I'm talking about.
Soo... Most coach roof raises don't increase the stuctural depth (and wall thickness) at all. Certainly the extra shear (skin) material adds some value back (and that's much more difficult to calculate)... but it's not usually enough to add back what's missing from the original structure by increasing all of those members' span in the first place.
Will a roof-raised coach, even a poorly done one, fail in a catostprophic way? Not likely. Are the original coach designs over-engineered? By a reasonable safety margin... yes, they are. Because they have to be.
Would I ever raise the roof of a coach? Nope. I'm just a bit too cautious.
But mostly I'm just lazy!
Brian
(Message edited by blue_velvet on May 20, 2006) |
FAST FRED
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 5:00 am: | |
The MCI is barely a Semi Monocoque.
While the sheer panels will eventually need to be reinstalled STRUCTURALLY , nuts & bolts or real (not pop) rivets , taking a ride home should not do a thing.
Those old coaches have plenty of framing structure to hold them together.
Around the windows is structural reinforcing , the windows are NOT.
Should be a "cool" ride home.
FAST FRED |
Doug Wotring
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 7:45 am: | |
Well I agree with you all somewhat......however I know that the bus twists when it is in it's original format.
I would not want to risk it without the windows. as there is no doubt that it will twist even more without windows.
30 year old metal....taking the windows out and there is very little structure holding the roof up.
I have seen photos of both GM and MCI coaches ( older ones) that have rolled and were put back on rubber towed home and new glass installed.
Roll one without the glass in and I can assure you it will crush like a tin can on it's side.
That is not to say you can't drive or tow it around the yard....but a drive home is a different animal |
Ross Carlisle (Rrc62)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 9:22 am: | |
Think about it...A window that is hinged to open and set in a rubber seal *can not* be a structural member. When MCI says that every part in the bus is structural, that's lawyer-eez for "Don't modify your bus....But if you do, we are not responsible."
No manufacturer of any product will tell you how to safely modify thier product. If they did and something happened, they could be held responsible. |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 10:58 am: | |
With the above observation by Brian, I must correct myself. Dave Galey's "Bible" comment was " but after you add the extrerior skin and the interior material the coach shell will be stiffer than the original bus."
Stiffer ain't necessarily stronger.
What I forgot to separate in my memory respecting my roof raise plans is/are, among other features, my plan to increase the height of the internal shear panels when I do a roof raise - to take advantage of the higher window sill height I'll be establishing.
Simple roof raise will increase stiffness. The panoply of changes I'm intending will affect more than stiffness.
It was incorrect for me to comment without making this distinction. |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 1:20 pm: | |
(shame on you) |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 3:06 pm: | |
John MC9, And I find that my shoes taste funny, also! |
Duane Kaler (Duane)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 3:32 pm: | |
Hi all, I want to thank everyone for their input and their thoughts. This board is an amazing resource to have access to. I tend to agree with Brian on the whole window discussion. So if my only issue is the missing internal skin, taking into account there is no passengers or cargo and that a fair amount of weight has been removed I feel it should be OK to make the trip home.
Duane |
Jay Gerlick
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 20, 2006 - 11:53 pm: | |
Why couldn't you Tek screw 3/4" plywood down each side over the windows? Support and less wind?
Crazy? |
Brian Brown (Blue_velvet)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 21, 2006 - 1:25 am: | |
Duane, there's a LOT of busses out there where the converters have removed the interior skin and only put back a fraction of the shear strength back in (with paneling, plywood, etc.). And those things roll down the road without serious failures.
You're right... you'll be fine.
Keep us posted on your trip and your conversion!
Brian |
FAST FRED
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 21, 2006 - 5:24 am: | |
Duane, there's a LOT of busses out there where the converters have removed the interior skin and only put back a fraction of the shear strength back in (with paneling, plywood, etc.). And those things roll down the road without serious failures.
We have to hope the second owner never moves the bus much.
FAST FRED |