Would anyone have pictures and perhaps instructions on what they did to mount seatbelts in their XK120/140 OTS? Is there a reinforcement “kit” available at any of the usual suppliers? I am only interested in lap belts and not shoulder harnesses.
Any suggestions and ideas would be greatly appreciated.
Thanks!
Chet
IMHO, a properly mounted seat belt should naturally lay across your pelvic bone, not up high over your abdomen/belly-button. In an XK120, I commonly see seat belt anchors installed into the vertical wall that makes up the front of the battery box. IMHO, this is very high up and causes the lap belt to right up too high on your body. However, this is also a VERY convenient place to install the anchors.
I did something slightly different. I put the outside anchor into the floor at the rear outside corners. If your car is undergoing a restoration, weld a plate to the frame back there and you’ll have a very strong attachment point. I didn’t so the eyebolt goes thru the plywood. But I used a metal backing plate that’s large enough to catch the edge of the structural sills so I think it’s likely ok in terms of strength. I put my inner anchors on that vertical battery box wall, backed up by a couple plates to spread the load. Then I ran that inside belt UNDER the fixed portion of the seat rail so it comes up further forward (inbetween the trans cover trim and the seat cushion). This gives me a less than idea but acceptable belt position that’s low and across my hips.
I also installed a shoulder belt (retractable) in the corner of the space where the side screens are stowed. I’ve seen them installed on the outside part of the flat part of the battery shelf. That’s a good choice, but it requires you to put a shoulder strap metal guide up by the bit bolt for the convertible top. I didn’t want to do that and the side screen storage bin is high enough that the shoulder strap angle is very shallow (as it should be).
Thanks John! Excellent advice regarding the placement of the seat belts. However, since my XK140 OTS is completely restored, I’m really trying to find a way to do this without welding a support onto the frame if at all possible. In my online searches I saw a reference to a support “kit” that might be available from one of the usual suppliers but all of the followup searches I did reveal nothing like that. Do you have any pictures of the attachment points you used for the lap belts?
Chet
I will try to have some pics…the bodywork metal is quite thin…not enuf to support the stresses of a crash. it takes a backing plate behind it…it does not have to be welded…just so it is there and the largest washers…you can find. try to find the strongest point in the bodywork that works out…where a plate/washers will fit. The anchors are everything…along with low ride placement as mentioned…I used the Simpson race belts.,.and yes…the two shoulder harnesses as well. Our cars do not have built in crash protection,.,.impacts would be hard. I was in a head on …in an 120 OTS…45 mph each car…so 90mph.,…and had the competition belts and harnesses…engine knocked off mounts…front tires blown.,.bent back to the doors…I had only one minor cut. I would not drive (and maybe would not be here at all) without the full set of belts. On passer side also,…as I value my passenger,. Belts can simp0ly be tucked away if you do not want them to be seen.,some have eye bolt clips to remove.,
Nick
The plate for the outside anchors is underneather the wood floor board and only visible from underneath and even then it’s not obvious. It does require you to slit the carpet though. I drive my xk a fair bit and prioritize safety over correctness. This is doubly so for the passenger -typically one of my kids, a friend or my wife. That’s why the passenger side has a retractable setup with shoulder belt. I will change my driver side over to this setup eventually.
We had a customer bring in a MK IV for a service. he’d put in front harness seat belts that were just bolted to the plywood floors. I said that’ll do bugger all good in a crash. He said he knew but just felt safer.
I’m not sure that feeling a false sense of security is a good thing.
When I worked in the ‘Federal Office’ we indeed had this argument with VicRoads, who were then hell-bent on introducing retrospective legislation on fitting seat belts to cars built prior to Jan 1965. The relevance of Jan 1965 is that was when legislation was introduced requiring all cars to first have front seat-belt anchorages fitted, which are as important to seat belt effectiveness as are the seat-belts themselves. The anchorages legislation dictates not just strength, but also geometry, so affixed seat-belts will actually provide their design protection in event of an accident. Seat belt anchorages in the wrong positions, can actually be counterproductive.
Regardless, VicRoads proceeded to locally require Seat belts to be fitted to all cars pre 1965, back to 1945 (I think - thus Mark IV) but have no requirements for seat belt anchorages (to hard basket for cars not designed/built with them), on the basis that anything is better than nothing. Unfortunately the science doesn’t actually support anything is better than nothing’ and indeed an incorrect seat belt installation can in certain circumstances cause more injuries/deaths than not having any seat belt; and indeed things such as wooden floors can elicit a ‘false sense of security’ as per Ed’s observation. A well engineered seat belt installation, where the geometry is within the limits of the applicable ADR, and the strength of the anchorages is as required by the ADRs, and the selected seat belt installed maintains the required geometry/position of the seat belt, is actually a good idea. But certain makes/models of cars, it is impossible to satisfy the geometry conditions. Its not something for the backyard enthusiast to cobble together.
Because my outer anchor is thru the floorboards I use a backing plate that’s sufficiently large to engage metal frame/sill to which the floors attach. Probably no good in a 35mph frontal crash (35mph Head on Into an immovable hard barrier. Hopefully enough to secure in a fender bender or mild roll-over. Relying on only the wood floor for strength is not enough. An alternative is to use a short length of SS cable (of a fabricated bracket) to secure the bottom end of the eye-bolt to a nearby frame via a second bolt.
I’ll disagree, slightly. There are (shade tree) enthusiasts (back yard ) that have enough common sense and knowledge to do a decent job of providing some added safety through the installation of passive restraint belts. With the internet at your finger tips, it isn’t hard to self educate a bit (rules and guidelines on installation of belts for racing sanctioning bodies is a good place to start).
John
IMHO the best place for the lap anchors is on the seat frame that moves as you adjust the seat fire and aft. But he requires the seat to be sufficiently strong and well attached to the car. On an XK120 that’s impossible. So I’d say the second best place for the outside anchor is the green scribbled area on this photo (on the floor, adjacent to the side of the seat base, biased to the rear but not behind the seat). To do this properly, I’d remove the floor and make sure there is a metal plate attached to the frame (or heavy L-bracket) for the end of the eyebolt.
I prefer eye bolts because a three point belt setup requires you to unhook the belt to erect or stow the hood. And with an eye-bolt you can quickly remove the belt and tuck it up not the side screen storage area when showing off your car.
Btw, about 15 years ago a family in Ann Arbor (Michigan) was badly injured (father died) when they were out in their open classic can and were struck by another driver. Mother father and one of three children died of their injuries. Police report all occupants were thrown from the car, and seat belts may have. Helped but were not installed. Duesenberg crash
To me this means a belt (which fits the occupant correctly) that helps keep you in the car, even if it’s not as strong as a modern OEM install, is a good idea.
Now if I had a 10 million dollar car whose value would be driven to zero by the installation of seat belts. It would go into a museum or I’d sell it. But an XK120 is worth at best $200k, and the health and well being of my family is worth the $1500 it would cost to fully and perfectly undo a proper seat belt installation.
And to quote a classic car article
Seat Belts and Originality
As far as I’m aware, there is no collector car club or car show organizer that will deduct points for the installation of seat belts in a vintage car. Most hobby organizations encourage the installation of seat belts as a way to save lives. The Antique Automobile Club of America maintains strict standards for training judges and judging cars at shows. AACA guidelines specify that points should not be deducted for adding seat belts to a car.
You most assuredly would not have fared well, w/o seat belts.
Chet,
Just for your info: the photos below show how I solved the issue for my XK 140 FHC during the “nuts and bolts” restoration when the body was still off the chassis. The curved middle section just fits under the prop shaft tunnel for the centre mounting point of two seatbelts. I guess this construction also suits the OTS models. For the upper mounting points: the FHC construction allows to install a square tube under the “parcel shelf” over the entire width. But this construction might be more difficult to apply for the OTS models.
Regards, Bob K.
Thanks everyone for your replies!
Chet
Roger,
I just checked as I am going to have to get a roadworthy soon and Vic Roads didn’t go down the road of making seatbelts retrospective. As long as the car is pre 69 it doesn’t have to have seatbelts unless originally fitted. Having said that you still need child restraints if you are going to carry a child, no matter how old the car is. Info in VSI21. If I am mistaken though let me know because I don’t want to hit a wall later.
All said and done though my 120 has belts fitted so I will be keeping them and upgrading the mounts if necessary. I think any mounts should be fitted to the body as in an accident if the body should shift on the frame the belt could crush you.
I will check the Australian Design Rules for correct geometry and mounting specification as a guide.
Final say is from the better half though who has given me firm directions.
Matt
Matthew,
Be interested in what your up-to-date experience with VicRoads.
My information that VicRoads did retrospectively require seat belts in 1965 cars was based on first hand knowledge/involvement about 15 years ago, and only casual confirmation since. I don’t live in Victoria (anymore). So maybe they have now relaxed this requirement, given it is not supported by Federal Law – thus my interest, and I can make inquiries when/why.
There is a special exemption in the ACJC National Concours Rules regarding a number of State Parochial modifications being allowed – for vehicles registered in that particular state only; and that did include Vic registered cars being mandatorily required to have seat belts. However, this was later engulfed with a blanket exemption allowing all cars to have seat belts fitted, even if not authentic – on safety and perceived safety grounds.
Regardless, racing harnesses are not allowed, not being legal on a road registered car, except for prescribed on-road racing/rally events.
And if you do install seat belts, pay as much attention to the geometry as you do to the strength of the mountings, and indeed selection of seat-belts you intend fitting.
I have fitted inertial-reel lap-sash seat belts into Mark 2 saloons, pre 1965, but never in an XK120/140, but doubt you would ever be able to put anything other than static lap-belts only in an OTS/DHC, without adding a structurally sound top mounting point. Top mounting point should never be lower than shoulder height, otherwise in a front accident you will be susceptible to spine crushing. But check the ADR5/ re geometry requirements of anchorages, as a necessary starting point, and ADR4/ for seatbelts themselves, albeit anything purchased from Repco (or similar) will be ADR4/ compliant. The issue will be satisfying ADR4/ re strength and geometry of mounting points.
Roger
We discussed the Duesenberg accident in 2005.
Here is another one.
I have lap belts in my 120FHC attached to the steel floor with big washers underneath.
Roger,
On the OTS several body panels come together at the front outside area that forms the side screen storage bin. I guess it’s not structural as none of the body is structural, strictly speaking. But with the inner fender, rear cowl, and the stowage tray all coming together is this area I felt it was the best of poor choices to mount my inertial reel. The belt is as high as I could make it without mounting the belt on the exterior of the the rear cowl. The angle of the shoulder (sash) belt is indeed rising but only at a modest angle for my passengers. For me it would be a bit more acute (and less optimal) but that is a limitation of the bodywork. I feel this is better than nothing.
Everything I’ve read suggests a modest rising angle for the shoulder belt is ok, and this is the OEM orientation on
Any coupes and cabriolets from the 1979’s and 1980’s (raven early 1990’s).
On my car I’ve currently fitted a lap-only static belt for the driver. I am concerned about the angle of a hypothetical shoulder belt, as you’ve mentioned. But perhaps even here there are mitigating factor such as the strength of the seat back and stretch of the belts (non-racing) that would make a steeper angle ok. I would never fit a race belt at an acute shoulder angle because they have vastly less stretch than passenger car belts, thus making them more likely to compress one’s spine in a frontal crash.
Well, that these comments for what they are worth, opinions of an amateur/hobbyist.
John
Rob
Sorry then for the duplicate post about the Duesenburg. It was before my time as a Forum participant.
John
A shoulder belt or belts should form a 90 degree angle, to the spinal column. Going down over your shoulders, towards the floor or a lower crossbar, defeats the purpose of the shoulder belt restraining you from contacting the dash and wheel, and can introduce compressive force injuries to the spinal column.
