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RichBusman
Advanced Member
453 Posts |
 Posted - 02/02/2012 : 10:28:43 PM
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Curious if anyone has an opinion on tempered vs laminated side glass on buses. Are there advantages and disadvantages to each? From what I understand, the laminated is quieter and blocks more UV rays.
Do any states require specific types of glass for side windows? NY simply requires that each window has the safety information on it to verify it is safety glass. |
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Fastback
Top Member
1500 Posts |
Posted - 02/03/2012 : 04:54:55 AM
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In Iowa you can use either.
Tempered glass weighs less and can be easier on the plastic window latches and other components especially on rough roads. The downside is when it breaks the window is basically gone, you have lots of little pieces to clean up and bus is out of service till repaired.
Laminated glasses advantage is that when it breaks it just cracks and unless something went clear through it, the plastic encased between the glass will hold it in place so it may save the day if bus is out on a route or away on a trip. |
Why yes, the ORIGinal CHARGER is a Fastback |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 02/03/2012 : 05:36:05 AM
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Ohio is now very specific as to the glass used on new buses. Anything behind the service door is required to be tempered. I agree with this requirement.
Extreme situation:
Reference the Alton, Texas bus crash of 1989. A 1985 Blue Bird AAFE, fully loaded, was struck by a semi, lost control and ended up submerged in ten feet of water in a gravel pit. None of the occupants were severely injuried in the crash itself, but a large number died from drowning.
This bus was equipped with laminate glass in all side windows positions. Passengers trying to escape, as well as emergency responders reported it difficult to impossible to break the glass fully out of the window frames. This was cited as one reason for the great loss of life by the NTSB.
An alternative view would be that laminate glass lessons the likelyhood of partial or full ejection during a crash sequence.
Just something to think about. |
Edited by - Thomasbus24 on 02/03/2012 12:38:31 PM |
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Fastback
Top Member
1500 Posts |
Posted - 02/03/2012 : 06:57:05 AM
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quote:
Originally posted by Thomasbus24
Ohio is now very specific as to the glass used on new buses. Anything behind the service door is required to be tempered. I agree with this requirement.
Extreme situation:
Reference the Alton, Texas bus crash of 1989. A 1985 Blue Bird AAFE, fully loaded, was struck by a semi, lost control and ended up submerged in ten feet of water in a gravel pit. None of the occupants were severely injuried in the crash itself, but a large number died from drowning.
This bus was equipped with laminate glass in all side windows positions. Passengers trying to escape, as well as emergency responders reported it difficult to impossible to break the glass fully out of the window frames. This was cited as one reason for the great loss of life by the NTSB.
Alternative thinking would be that tempered glass lessons the likelyhood of partial or full ejection during a crash sequence.
Just something to think about.
Isn't that the opposite? Laminated glass should lesson the likelyhood of ejection during a crash. |
Why yes, the ORIGinal CHARGER is a Fastback |
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RichBusman
Advanced Member
453 Posts |
Posted - 02/03/2012 : 08:18:16 AM
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Interesting points. NY allows either type of glass, and most everything is tempered.
I too would think that laminated would have less ejections. Is there any reduction in road noise as well? What about insulation effect?
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 02/03/2012 : 08:59:34 AM
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| I wouldn't think there would be much difference with regards to sound or thermal abatement, but I'm no scientist! |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 02/03/2012 : 09:06:19 AM
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You know what Rich, I gave you bad info on this matter. Laminate is acceptable in passenger windows. Sorry for the mistake.
Here is the copy-n-paste of the rule from the construction standards:
(X) Glass.
(1) All glass shall be manufactured and maintained as follows:
Glass table
Location Glass type Rating
Service door Laminated AS 1 or AS 2
Emergency door Tempered or laminated AS 2 or AS 3
Emergency window Tempered or laminated AS 2 or AS 3
Windshield Laminated AS 1
Driver’s side glass Laminated AS 1 or AS 2
All other glass in passenger’s area Tempered or laminated AS 2 or AS 3
Exception- On “Type A” buses the driver’s door glass shall be manufacturer’s standard.
All other glass not noted in table shall meet Federal Motor Vehicle Safety Standard 571.205 Glazing Materials.
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bluebirdvision
Top Member
USA
1081 Posts |
Posted - 02/03/2012 : 09:14:56 AM
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| I have had 2 Coach & Equipment buses (commercial) that the entire service door glass shattered, for no apparent reason at all... The driver just shut the door, and the glass shattered. It was a MESS and glass flew EVERYWHERE. It must not be laminated glass. |
Facebook Page: Blue Bird Corporation Fans
https://www.facebook.com/home.php?sk=group_212311114614&ap=1
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Edited by - bluebirdvision on 02/03/2012 09:15:59 AM |
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JRob
Advanced Member
207 Posts |
Posted - 02/03/2012 : 11:17:14 AM
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Thomasbus24, you have hit the nail on the head. Tempered is the preferred glass for side windows because of the fact it is 5 to 10 times stronger than un-tempered glass yet can be broken out by safety crews in case of emergency. Additionally, the tempering makes the glass break into small, pebble-like pieces which is safer.
Laminated glass is better from an ejection standpoint and is used in windshields because it is shatter resistant. It is also heavier which can have capacity implications in some instances.
Ejection through side windows in buses is usually accompanied by catastrophic body intrusion vs. simply the glass in the window glass breaking. . |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 02/03/2012 : 12:37:48 PM
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quote:
Originally posted by Fastback
quote:
Originally posted by Thomasbus24
Ohio is now very specific as to the glass used on new buses. Anything behind the service door is required to be tempered. I agree with this requirement.
Extreme situation:
Reference the Alton, Texas bus crash of 1989. A 1985 Blue Bird AAFE, fully loaded, was struck by a semi, lost control and ended up submerged in ten feet of water in a gravel pit. None of the occupants were severely injuried in the crash itself, but a large number died from drowning.
This bus was equipped with laminate glass in all side windows positions. Passengers trying to escape, as well as emergency responders reported it difficult to impossible to break the glass fully out of the window frames. This was cited as one reason for the great loss of life by the NTSB.
Alternative thinking would be that tempered glass lessons the likelyhood of partial or full ejection during a crash sequence.
Just something to think about.
Isn't that the opposite? Laminated glass should lesson the likelyhood of ejection during a crash.
DOH!!!....that is what I meant to type!!!!!
That's what I get for posting on the fly I guess. |
Edited by - Thomasbus24 on 02/03/2012 12:40:45 PM |
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bwest
Administrator
United States
3820 Posts |
Posted - 03/27/2017 : 05:44:34 AM
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| I am currently trying to gather information regarding laminate vs. tempered glass. I didn't realize we had talked about this on this forum. Wondering what you all think? I am still of the opinion that laminate would be better in most instances. I have two emergency windows per side, two roof hatches and a rear door for emergency exit. I don't see any reason to need to break out the side glass in an emergency situation. Where am I going wrong here? |
Bryan |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 03/27/2017 : 08:16:25 AM
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| Submersion, fast-spreading fire or some other fast approaching danger are the only reason I come up with. All would be extremely rare. |
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bwest
Administrator
United States
3820 Posts |
Posted - 03/27/2017 : 09:12:56 AM
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| As is an overturn where the windows come out and a child or children are ejected. However, it's a big blanking deal when it's your child. My biggest fear is that we get seatbelts and then a big accident happens and there are kids taken from us, because of the belts, who otherwise would have lived. |
Bryan |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 03/27/2017 : 09:24:15 AM
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quote:
Originally posted by bwest
My biggest fear is that we get seatbelts and then a big accident happens and there are kids taken from us, because of the belts, who otherwise would have lived.
My state's fatal a few years ago was the double-edged sword. I can only speculate from what I took from the report, but a 3-point belt likely would have prevented the young child's death, but would have ensured an older child's death.
http://www.schoolbusfleet.com/forum/topic.asp?TOPIC_ID=21271
Reference post #7 |
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bwest
Administrator
United States
3820 Posts |
Posted - 03/27/2017 : 10:30:01 AM
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| Interesting. The question then becomes this; what kind of life altering injuries are there going to be with seat belts as opposed to without? Also, are we trading one life for another (as in the event you illustrated in 2011)? The bottom line is; we aren't going to prevent all deaths. The industry has done a great job in minimizing them though. Another thing to factor in is this; are we going to make the average age of a school bus go up because of the added cost of seatbelts? i.e. will the cost prevent the regular replacement or at least slow it? |
Bryan |
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Titan1
New Member
7 Posts |
Posted - 03/28/2017 : 11:07:53 AM
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Interesting read. It doesn't matter what type of glass you use the window must still meet the FMVSS for windows. Texas requires a full laminated glass package and besides the weight the extra cost is burdensome as well. For entrance doors alone the laminated is close to a $300 upcharge.
I don't see the added benefit from going to laminated. |
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Tempered vs Laminated Glass
