Classic cars forum & vehicle restoration.

[Ray White]

I am hoping someone can give me advice on what type of seat belts to fit to my MG TC.

My dilemma is that these cars were not only built without seat belts but with no means of fitting them. This wouldn't be too big a problem with a saloon car but in an open top sports car with a wooden body the location of the fixing points is limited.

There are debates about whether two or three point belts are best given the limitations. The argument against a lap belt is that in a head on crash it does nothing to prevent the driver's upper body from being crushed against the steering wheel...and without a collapsible steering column this could be fatal.

The argument against a three point belt is that if the feed angle is lower than shoulder height; say, in line with the seat base (mounted on a wheel arch for example) the restraint forces are downward and the belts themselves can cause spinal injuries.

In the case of the TC (due to having a wooden frame) the only place for the upper anchor of a three point belt is the wheel arch.

Incidentally, the Society for the Prevention of accidents consider it safer to have a lap belt than no belt at all as most serious injuries are caused by people being thrown out of the car.

(Ironically, I remember Sterling Moss saying that in his day racing drivers eschewed seat belts; believing that being thrown out would be the best outcome.!)

My problem is I don't know which would be the safer bet in the T.C. being used as a road car.

Note: I will not be fitting a roll bar.

[ukdave2002]

Hi Ray

What sort of accident are you planning to have? knowing this will help determine the best restraint

On a serious note, I guess any restraint is better than none (in the case of most accidents) and even a lap belt must reduce the chance or damage of being crushed against the steering?

The adjustable steering column on your TC would offer a bit of collapse as long as it’s not fully retarded.

As you indicate the challenge of fitting a 3 point is the lack of anything solid at the right height, you could fit a roll hoop? That would obviously offer some rollover protection, but also provide a solid mounting for a 3 point belt.

All options are a compromise one way or an other, my view (and I’m not an expert by any means) is that a 2 point belt is probably the best comprise between aesthetics and safety.

Dave

[mikeC]

Unless you are going to fit a steel roll cage and fasten that and the seatbelts directly to the chassis I can't see that the belts are going to offer any real protection in an accident. They may well give the driver and passenger a greater sense of security, but I doubt they have any real benefit. Many years ago an engineer friend was involved in a relatively minor accident in his Austin Seven; he had fitted seatbelts securely to the cars floor and timber body frame. All that did was to rip the body apart and he still went through the windscreen.

Stirling Moss' comment reflected the dangers of an accident in the 1950s - there was a greater chance of surviving being thrown out than being trapped in a burning wreck.
_________________
in the garage: 1938 Talbot Ten Airline
Recently departed: 1953 Lancia Appia, 1931 Austin Seven, 1967 Singer Chamois, 1914 Saxon, 1930 Morris Cowley, 1936 BSA Scout, 1958 Lancia Appia coupe, 1922 Star 11.9 ... the list goes on!

[Ray White]

Good morning Dave. I doubt I am any more likely to have an accident in the TC than in any other car. That said, the only crashes I have had are rear end shunts; something that I have no control over and which with a slab tank could be the last one.!

I am aware that with a minor rear end shunt in a car without head restraints, there is a risk of whip lash.

As I said, I will not be fitting a roll bar so I have to choose between a lap belt with it's limitations or a three point belt mounted incorrectly with it's supposed risks.

Your thoughts in favour of a lap belt is noted... however your point about the steering column doesn't apply as what little adjustment there is needs to be clamped tight.

[peter scott]

Personally I wouldn't fit belts or a cage but it sounds like your best option would be to wear a crash helmet and fit lap belts.

Peter
_________________
https://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[Ray White]

Mike. Rest assured that any seat belt attachments I fit will be substantial and not anchored to any wooden parts but there is a risk that the body could be ripped from the chassis - it has happened to this car before - and that could actually make a seat belt an additional hazard.

The real problem is me.

I have become too used to wearing a seat belt.

[alastairq]

Safety is no less compromised than if one was using a motorcycle.
Possibly the best safety-orientated plan is to do what decades [and decades?] of designers and litigators have achieved, and go buy a brand new open top two seater and use that instead?
Solves most of the issues raised in one fell swoop!

No amount of risk-reduction will account for the drugged-up looney driving the wrong way down the wrong side of the road at high speed. If they hit, head-on, any old car then no matter how many seat belts, cages or fire extinguishers it has, the outcome is inevitably going to be a fatal one.

Partly because most of the drivers [I think it is safe to say??] of old open [sports] cars like the MG [or a Dellow?] will be well past the so-called 'middle' age...in fact possibly into the 70's or 80's...so will be less able to withstand even nominal shocks to the system, that a youngster in their 20's will just shrug off.

Older folk are less likely to survive the trauma.

Perhaps, for ideas of how to mitigate the safety issues, one might take a look at what Morgan did back in the 1980's and 1990's, to accommodate safety features in a car built on a chassis, with wood framed bodywork?

My Dellow has a roll-over bar. It was fitted during it's sojourn as a 'racer' in the USA... It also had a single lap belt fitted, secured to the tubular body frame. A massively wide aircraft type, of no use whatsoever in my mind, yet it satisfied the US [SCCA?] rules....

I have lowered its height somewhat, so the hood can actually fit over the top of it...[it was sized to fit over the head of a driver who was 6 foot 5 inches tall!! I'm only 6 foot 2 inches tall!] The belt is of no practical use as I cannot physically be lifted out of the driver's seat, so cramped is the cockpit.

For discreet roll-over protection I think nothing [of a limited production] can beat the original Marlin kit-car!

The original design Marlin, the brief of which was it should be able to withstand the rigors of Classic Trialing, involved a windscreen frame engineered to double up as a roll over bar to protect the occupants in a roll over.


It's a hazard of growing old, methinks?
_________________
Dellow Mk2, 1951 built, reg 1952.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
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Ford Pop chassis, Ashley 1172 bodyshell, in pieces.

[Ray White]

[Keith D]

I am not familiar with the road laws in the UK regarding fitting of seat belts, but is it legal to fit seat belts in a car that has no fixings designed and built into it when new for seat belts?

I question this only because in Western Australia it is a definite no-no legally. Old cars cannot have seat belts or baby seats fitted. Engineered seat belt and baby seat anchorages first appeared in the sixties. And we are not allowed to drill holes in car chassis either.

Keith
_________________
1926 Chrysler 60 tourer
1932 Austin Seven RN long wheelbase box sedan
1950 Austin A40 tourer
1999 BMW Z3
Its weird being the same age as old people.
You are either part of the problem or part of the solution

[Ray White]

[alastairq]

TAking a look at what mainstream manufacturers did/still do, regarding seat belt anchorages, I'd say drill a hole, double plate it, and hawaaay you go? MAybe make a captive nut?
Where seat belt anchorages really hurt is at MoT time, when one has rust [rot?] less than 30 cm from a seat belt anchorage? Often regardless of what piece of metal the rot is actually on.
_________________
Dellow Mk2, 1951 built, reg 1952.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
----------------------------------------------
Ford Pop chassis, Ashley 1172 bodyshell, in pieces.

[Ray White]

[ukdave2002]

Hi Ray

Here is a link to a guide on fitting 2 & 3 point seatbelts to an MGA. I appreciate its a later car than yours, but it gives some insight into how MG first approached seat belt mounts from the factory, it also looks at some of the later aftermarket kits. Interestingly the factory MGA centre anchors are on the prop-shaft tunnel which like the TC is pressed steel.

https://mgaguru.com/mgtech/interior/int120.htm

Dave

[alastairq]

The propshaft tunnel might b easy enough to fit re-inforcing sheet steel to? It is an arch-shape, after all?

When working out whether a mounting area is strong enough for a seat belt anchorage, one has to wonder just what stresses were reckoned to be applied at each mount? Are the stresses of restraint shared over all the mounts? Or purely localized as a maximum?
How many times does a seat belt anchorage have to withstand the stresses of a seat belt actually being 'used?'...

On my Cannon, [trials car] which I had to work up to the specifications in place around 1996, in order to obtain a registration number [it is a Cannon built sometime in the 1950's...Cannon didn't exactly keep records of his production, nor did he apply chassis numbers!
It has pre-WW2 suspension and fittings for a sidevalve Ford engine] I had to work up and fit seat belts. these are inertia reel belts [Ex-mini, IIRC? They could be had new, very cheaply back then]... The inertia reels located immediately behind the rear bulkhead {!}, to a gusset welded in immediately behind the Cannon chassis upkick ....
[The entire rear behind the seat back area is purely small tube framework to carry body panels and support fuel tank and battery...the chassis proper ends under the drivers backside, kicks up & across, to carry the coil spring mounts, shock mounts and panhard rod mounts...]

For the central mount for the short belt & clips, I had welded in, from small size [square, all I had in stock] tube, to form a frame for the transmission tunnel...and 'safety 'idea I had as the prop shaft was whirling a mere few inches below ones elbows, and if it came adrift, I wanted something a bit more substantial than thin ally sheet between my elbow and the whirling shaft!! I found a scrap piece of thick walled {?} large diameter steel tube, only about 3 inches long, but it sat over the three longitudinal tubes, welded in place....with a single, thick piece of steel, drilled to take a big bolt [bolt sizes for me were big, small, and smaller, back then] to which were fixed the short belt [mini] ends...
To test my weldmanship, I have lifted the entire rear of the car [complete] using a chain hoist, solely on that central mount.

Nothing went twang, so I reckoned it would pass muster. The Tester didn't quibble either.
I didn't see the sense of making two central mounts [there wasn't space anyway] so mounted both short belts off the same bracket.

You might be able to work up something similar off a cross member, with a U shaped bit of steel?
_________________
Dellow Mk2, 1951 built, reg 1952.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
----------------------------------------------
Ford Pop chassis, Ashley 1172 bodyshell, in pieces.

[Ray White]

Interesting solution, Alastair. On my car the prop shaft tunnel could be reinforced (I did that at the front end when I modified it for the T9 gearbox) but the problem is the feeble 1/4" fixings that attach it to dinky brackets on the cross tube either side of the prop shaft.

The easy answer, of course, would be to attach it to a heavy duty steel plate behind the diff ramp ... but as the body itself has been known to rip it's fixings out of the outriggers before, there seems little point in relying on that to hold either.

This has given me another thought which might put the whole idea into the bin. If the body tub can fly off the chassis in an accident - and the seat is secured to it - any belt fixed to the chassis could do more harm than good.