Did I get it right? https://youtu.be/KlwhE-bTX58
Seatbelts Y/N?
- Thread starter P.S.
- Start date
kbinde2
Senior Member
I have installed seatbelts in my '29 Coupe, and also added turn signals. I agree that there is probably more we could do, such as the addition of a 2nd lighting fixture on the right rear fender, and maybe a brake light in the rear window.
I feel I am more sure of my driving habits and road posture, than I am of those driving around me. I think we hone our driving skills every time our A's are on the road, driving more defensively and certainly aware of our presence on todays roadways.
I feel I am more sure of my driving habits and road posture, than I am of those driving around me. I think we hone our driving skills every time our A's are on the road, driving more defensively and certainly aware of our presence on todays roadways.
nkaminar
Well-known member
Seat belts (lap belts) will keep you in the car in the case of an accident. It will not keep you from hitting the steering wheel. In my opinion they are worth having. What others have said is correct. Model A's are not nearly as safe as modern cars. But driving habits will go a long way to improve your odds.
alexiskai
Well-known member
IMO we tend to overthink the frame/body dilemma. It is true that the body could theoretically detach from the chassis in an accident and it is true that there are period photos of this occurring. However, consider that those photos probably overrepresent the frequency of that type of accident. It's a very dramatic image!
But we have no data on how often that really happened at the time or how often it happens now. I have not heard of any Model A body-detachment accidents in the recent past. The vast majority of accidents I've heard of involve:
- doors open without warning
- driver loses control and hits curb/tree/ditch
- low speed collision at intersection
In these scenarios the most critical objectives are to keep the occupants inside the cabin and prevent them from hitting unyielding elements of the car like the body supports or steering column. This is true even for open-car designs, as the accident investigator commenter on your video showed.
To achieve both these objectives, you really need a shoulder belt, but that's not always possible, so let's set that aside. To optimize the restraining function of a lap belt, the belt needs to keep as much of the occupants' mass as possible from moving forward within the cabin. This is quite hard, as you'll see if you watch any of those slo-mo videos of crash test dummies. Our goal is to reduce the severity of any injury by preventing the center of the body from hitting anything.
The force on the belt at the instant of impact can be several times the weight of the occupant. If you have the average 60-year-old married couple in a bench seat, that weight is 372 lbs. Add to that the weight of the bench seat itself. So the reinforcing steel that you install needs to be sufficiently robust to deform minimally or not at all under, let's say, 1500 lbs of force, which might be applied off-axis. If it deforms, then the occupant will stay inside the cabin but more of their mass will be moving forward or sideways, causing greater injury when they hit the firewall or the steering column.
So now here is where I differ from your method. I think we should recommend that people attach the seat belts to the chassis because:
- Most owners are not engineers.
- Owners will tend to underestimate the amount of reinforcement required to successfully restrain them in an impact.
- Reinforcing via the chassis is much more likely to provide sufficient reinforcement.
- The risk of this backfiring because the accident is so severe that the body detaches is incredibly small, much smaller than the risk that the owner under-designs the reinforcement, leading to the belt attachment point deforming and the occupant being more severely injured through impact with the windshield, door, etc.
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mhsprecher
Well-known member
I am with you on this and it is what I have done. I used the seat belt mountings from what was Juliani's. Les Andrews covers this in his green volume 3, which is what I did. He suggested adding a metal strip on the underside.
I have belts in my 28 roadster. To me, staying in the car is key. In any event, you don't want to be in an accident in a Model A.
I have belts in my 28 roadster. To me, staying in the car is key. In any event, you don't want to be in an accident in a Model A.
Clem Clement
Well-known member
The late Benny Lenoard and I welded a piece of angle iron to the frame of my 30 Model A cabby. Onlyway Ms Sandy would ride with me. Clem
This is the kind of dialogue I was hoping we could have. Thanks, Alexis!
I thought about running some numbers on this and maybe doing a simulation this winter when things slow down at work. Might be fun to find out for sure about what it takes to forcibly separate the body off a coupe, for example, in simulation and see if that would be survivable.
Yes. I no longer own a motorcycle.
David in San Antonio
Well-known member
As recently as the 1960’s at least one car company advertised their pop-out windshield. I think it may have been for the Sunbeam Imp.
alexiskai
Well-known member
I thought about the scenarios in which this might happen. Remember that the Model A frame is itself relatively light and flexible. It'll want to try to stay with the body in a simple rollover. Most likely situation I thought of is one where the body is moving and the frame stops, or vice versa, with sufficient deceleration to pull the body bolts through the panels (I assume the panels will yield before the bolts do). Or the body and frame try to move in different axes. So for example, maybe hitting the back of a semi-trailer at high speed? Or a multi-vehicle accident in which the car is hit from two directions.
Maybe if you're a dirt track racer. Every accident report I've ever read, being thrown "clear" is what got people the most heavily injured.
The Geezer
Senior Member
I'm with P.S. on this and installed seat belts on my current 31 Sport Coupe, attached to the body. Back when I was 18 (62 years ago), the door on my buddy's Model A opened when we went around a corner on the way to high school! I fell out but wasn't severly injured. My buddy heard a noise and looked over...and I was not in the passenger seat anymore! We still laugh about it today, but because I was lucky and not hurt. So yes, the first thing I did to my Model A when I bought it 3 years ago was to install seat belts. Lesson learned early: doors CAN open in these vintage cars!
The Geezer
The Geezer
The Geezer
Senior Member
Absolutely!
Thanks, The Geezer
Thanks, The Geezer
Marshall V. Daut
Well-known member
As recently as the 1960’s at least one car company advertised their pop-out windshield. I think it may have been for the Sunbeam Imp.
The 1948 Tucker "48" had the same feature: a pop-out windshield upon impact by front seat occupant(s). Other safety features were also built into this car, such as a "crash cockpit" for the front seat passenger to dive into when a collision was imminent. As I recall, only four Tuckers have not survived of the original 51 production Tuckers. I think one or two were purposely destroyed, such as prototypes.
Marshall
The 1948 Tucker "48" had the same feature: a pop-out windshield upon impact by front seat occupant(s). Other safety features were also built into this car, such as a "crash cockpit" for the front seat passenger to dive into when a collision was imminent. As I recall, only four Tuckers have not survived of the original 51 production Tuckers. I think one or two were purposely destroyed, such as prototypes.
Marshall
Talking about purposely destroyed. Just last night, I saw something on the 1963 Chrysler Turbine car. About 50 were made, and Chrysler destroyed about 43 of them.
What a waste. A while ago, Jay had a turbine on his program.
About 10 years ago, I went to a car show sponsored by a mechanical college. They had a 4 Vipers that they used for training. They told me that Chrysyer sent them a legal letter telling them they had to ship the cars back to be destroyed, otherwise they would lose funding, and get sued.
What a waste.
What a waste. A while ago, Jay had a turbine on his program.
About 10 years ago, I went to a car show sponsored by a mechanical college. They had a 4 Vipers that they used for training. They told me that Chrysyer sent them a legal letter telling them they had to ship the cars back to be destroyed, otherwise they would lose funding, and get sued.
What a waste.
rich b
Well-known member
A friend of my son's, rolled his cabriolet back in the day, didn't get "thrown free" and ended up stuck inside of it for several hours.
Eventually his buddies came looking for him, found the car in the ditch and rescued him.
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alexiskai
Well-known member
Was he OK?
rich b
Well-known member
Yes; Louis said he was unhurt, just trapped as the windshield frame and door tops sank into the swampy ground.