Low Volume Vehicle Certification » Seats and Seatbelts

Aftermarket seats – the seatbelt buckle problem

johnbrett — Wed, 14 Mar 2012 08:14:44 +0000

Mnay enthusiasts want to fit aftermarket seats to their cars.
A problem arises when the original seat has the seatbelt buckle mounted on the seat, so that the seatbelt load goes through the slide rails to the car.
The easiest option is to keep the original slides, and mount the new seat to them. This way the seatbelt anchorage is unchanged.

If this is not possible, and the aftermarket seat has its own base and slide rails, this is where the problem arises.
There needs to be TEST DATA to show that the aftermarket rails are strong enough for the seatbelt load- and THERE NEVER IS ANY TEST DATA

There are two ways around this:
1 Fit a new Seatbelt Anchorage to the vehicle tunnel. This is done using standard Seatbelt Anchorage doubler plates of at least 3000 sq mm area (such as 80 x 50, or 100 x 40).
2 Bracketing the seatbelt buckle to the seat anchorage, using a piece of 40mm x 3 mm flat bar, usually about 100 to 150mm long, drilled for the 7/16 seatbelt bolt at one end, and drilled to fit the seat mounting bolt (usually M10) at the other.

It is a requirement that the Seatbelt is mounted with a 7/16 or M12 bolt. There are good reasons for this, and the seatbelt hardware is all made for this size of bolt.

The seat mounting bolt is whatever the vehicle manufacturer deemed appropriate- a M10 grade 8.8 bolt can take a shear load of 48 Kn, which is more than meets the load requirement for a seat and the seatbelt buckle loading.

The Manufacturers underfloor mounting plate for the seat is designed to take this load- the picture below shows that the seatbelt load in a standard seat is transmitted just to this one bolt- proving that this is true.
So we can rely on the Original, Factory seat mounting point, and the Original seat mounting bolt to take the seatbelt loads, the load just gets there by the new bar we have added.
NOTE- Remember to put the seatbelt load bar between the seat and the tunnel or floor.

S14 Seat showing Force Diagram

The LVV Standard for seats is 185-00. The LVV Standard for Seatbelts and anchorages is 175-00

Vehicle Design Consultancy Launched!

johnbrett — Tue, 28 Feb 2012 21:49:24 +0000

When you have been doing something you enjoy for years- something which is in constant demand- perhaps it is time to call it a business and give it a name!
John Brett has been designing vehicles from WAAY back- starting in the Ministry of Works at Benmore, designing all manner of ambitious and way out vehicles, but under the supervision of some of the best Mechanical Engineers in the country. How about a Penstock transporter, or a Hot-rodded bren-gun carrier for the televiewers association to get to their TV translater!

His career took him to Certified Concrete, where he designed some revolutionary (joke) concrete mixer trucks, which were used all over NZ, including a twin-steer model that discharged over the top of the cab!
His interest in cars led him to Todd Motors in Petone, where he was Tooling and Equipment Engineer, for 5 years, basically designing complete assembly facilities, including paint, body, mechanical assembly, also Tooling and pre-production of such exciting new models as Hillman Avenger, Valiant Charger.

Fords made a better offer, and John spent 5 years as Process Engineer, on things like Falcon, Cortina, Escort, Transit and D-series trucks

John then joined the NZED/Electricorp, initially designing big transmission lines (Pylons etc), before getting into Gas Turbine Power Stations. John was involved with Stratford, Whirinaki and Otahuhu Power Stations, but did work on other Thermal stations as required. John started NZ Manufacture of Turbine parts, worth millions per year, including completer Curtiss Wright Turbine Stator casings

John has been operated as a VSRCE from 1997 to 1999 doing Entry Certification. He has been a Low Volume Vehicle Certifier since 1999, and Certified around 4500 vehicles, and built a large and loyal customer base.

John is now offering a Vehicle Design Consultancy, separate to the LVV Certification.
More details on this page.

EMISSION LEGISLATION WILL FORCE CAR PRICES UP, DO NOTHING FOR AIR CLEANSING, SAY DEALERS:

Global Online Cars.com — Wed, 30 Nov 2011 04:11:52 +0000

The National Government’s proposed emissions rule legislation has so upset the second-hand motor vehicle industry that they’re going to seek signatures for a petition nation-wide, using social media to make their point to the politicians.

One importer — Global Online Cars — is producing The Car Info Show for YouTube, and its promotional video asks National party politicians three questions about the consequences of the legislation. They are:

‘How do you think this new emission rule will clean up the quality of air in NZ and benefit the NZ public?’

‘Why are we not considering an annual ‘In service emission testing’ at WoF when there are 20 major cities up and down the country geared up with certified equipment and proven research ready to improve NZ’s quality of air?’

‘Stephen Joyce — will you be willing to accept responsibility for the expected increase in the price of cars?’

The Car Info Show is aimed at showcasing the progress of the motor vehicle industry in New Zealand over the past 30 years but host Chris Jellie’s main focus over the past six months has been on the downside of the Emissions Rule, and its subsequent inability to achieve its desired result.

Importers and second-hand dealers agree the Emissions Rule fails because it limits 85% of fresh imports from Japan, says Jellie, reducing the majority supply of fresh cars to New Zealand. And it includes all imports no matter the country of origin.

‘People are just going to hold onto their old, clapped-out hunks of junk’ he quotes Liam Graham of Wanganui Car Centre as saying, after pointing out over 95% of his stock would be banned by the Emissions Rule.

‘The Emissions Rule is going to make the air quality worse,’ said Jellie. ‘It’s just going to restrict fresh imports, push the prices of available imports up, and force the average New Zealander to keep their old, beaten cars because they can’t afford to upgrade.

‘These fresh imports are vital for New Zealand — we scrap 150,000 cars a year.” he said. “With the decrease of fresh imports proposed by the Emissions Rule, there just won’t be enough cars to fill demand.

‘You, the buyer, will be facing the stupid Emissions Rule. You won’t be able to buy these cars in these price ranges again’ was the view of Rod Milner, Rod Milner Motors, Auckland.

‘The average age of our national fleet is about to become older than 15 years,’ said Jellie. ‘NZTA’s own web site now states the average age a vehicle gets scrapped is 18. As a result the average price of cars, for the Kiwi family, is going to jump between $4000 and $10,000 because of the Emissions Rule.

‘So watch the “3 questions for the National Party” video and click on the petition after watching, to have your say New Zealand.” Jellie said.

The video link is The Emission Rule – Latest News – Government Ignores Proven Emission Test For NZ

Vehicle crash performance

johnbrett — Fri, 01 Oct 2010 06:00:21 +0000

This startling video illustrates the advances in car design for accidents.

The first obvious lesson is which sort of car to be in- if you have a collision

The next lesson is for anybody modifying cars- to understand the level of technology-
For example- if you were fitting seatbelts to the Bel Air, or a Morris Minor, (as you would be required to in New Zealand)- you can only work to achieve the best seatbelt anchorages possible, attached to available structures, and hope to give some increased protection in smaller crashes.

For example- if you were fitting seats and seatbelts to a MODERN vehicle, (say a Van) you need to be able to show that the modifications WILL WORK in the sort of impact shown in the video. Imagine LVV Certifying a Van with extra seats, extra seatbelts, wheelchairs and occupants and restraints- no wonder customers frequently question why it all needs to be so strong!

For example- if you wanted to change anything about the frontal impact structure or systems of a modern car (whether it is a Chev Malibu, or Toyota Yaris), how would you know if the crash performance will still be the same?
That’s why you can’t cut away the front bumper, add a different front bumper, trim the flanges off side-rails to add a front-mount intercooler, or cut holes in the crumple structure, etc.
You also cannot go adding stiffness in a crumple area, such as a suspension brace which stiffens up areas meant to fold.
The change you make could cause that part to fold, or maybe transmitting the load to another part making it fold instead, or triggers the airbags differently, and resulting in impaired performance and injury or death- HOW WOULD YOU KNOW?

EXAMPLE The “push bars” on some Police traffic cars would have been crash tested, and have documentary evidence of the test.

This video shows why modern cars are so surprisingly HEAVY, (compared to similar cars of the 1970′s and 1980′s which were NOT crash tested) and why there is so much high-tensile steel in the vehicle structures.

That is why Low Volume Vehicle Certifiers cannot certify any modifications in frontal impact structures and systems because the ONLY way to prove the case for or against would be to carry MORE crash tests- which is outside of the scope of the Low Volume system.

Motor-home warning

johnbrett — Fri, 05 Feb 2010 20:42:46 +0000

Burstner, Adria, Arrantea and similar European makes of motor homes may NOT be legal for New Zealand roads.

Burtner Camper- non compliant for NZ

The Low Volume Vehicle Technical Association has decided that seat structures made of wood or fibreglass DO NOT MEET THE LOW VOLUME VEHICLE STANDARD 185-00.
Even if the vehicle has been approved for use in Great Britain or other EU Country, it may not meet the requirments for New Zealand.

If the vehicle is a HEAVY VEHICLE, (over 3500kg GVM) this ruling does not apply.
If the vehicle has a “Whole of Vehicle” Compliance document or plate, this ruling will be avoided, since the Low Volume Vehicle process is avoided.

Here are examples of Camper Van seat construction:

This is the seat structure in a Burtner Motorhome, the MDF seat structure is sunstantial, and fixed to the steel Seat Belt Anchorage frame. The water-tank is also mounted into this structure.

This is a side-berth in a Toyota Hiace Camper Van. The weakness of this is obvious- the frame is only fixed down with small woodscrews to the false floor. This is NOT SUITABLE for a seat, a seat-belt SHOULD NOT be fitted in this vehicle.

If a Camper Van or Motor Home has to go through the New Zealand Low Volume Vehicle system, it will need :

1 A Seating position with a seatbelt for each sleeping berth- (e.g. If 4 berth, this means two seats ADDITIONAL to the two front row seats.)

2 Evidence that the Seat-Belt Anchorages have been tested to the required standards.

3 Seats made from wood, plywood, MDF, Fibreglass etc REPLACED OR FRAMED OUT in steel.

Low Volume Vehicle Seatbelt Anchorage Standard
Low Volume Vehicle Seat Standard

Seats and Seatbelts in a Van

johnbrett — Sat, 27 Jun 2009 08:05:14 +0000

Fitting seats and seatbelts to a van requires design to meet the loading requirements in a frontal collision.

Van seatbelts - view from side

The LVV Standards for seats and for seatbelt anchorages set out the different ways of meeting these requirements.

In the Hiace shown, some second-hand seats were to be fitted, these had the seatbelt anchorages in the seat frames, making them “Stressed Seats”. This is much neater than having all the seatbelts going to the floor, however it means that the seat has to be strong enough to take the seatbelt loads.

Van seatbelts - view from rear

A quick stress calculation showed that the back beams were not strong enough, and had to be strengthened by adding a 50 x 25 box beam to the original 50 x 50 box beam to make a 50 x 75 box beam.

The mounting system is the “Over-floor mounting bar” system, as in the LVV Standard.

Also visible are headrest mounts on the rear seat back, because of the closeness of the rear window.

Installation by owners Eastern Rentals 66 TeRakau Drive 09 577 0128
Design calculations and LVV Certifification by John Brett Technology Ltd. 0800 LOW VOLUME (0800 569865)

The LVV Standards are here- Seats and seat anchorages [692kB PDF] and here Seatbelts [1024kB PDF]

REAR FACING SEATS
Rear facing seats have to restrain occupants from frontal impact. This means that the seat backs have to be far stronger than normal, or a supporting structure provided.
This is a matter which is often overlooked by some commercial modifiers.

The requirements from ADR VSb 5B are:
Appendix B
Rear-Facing Seat Strength

Rear-facing seats and their anchorages must comply with the requirements of the latest edition of ADR 3/…
In addition, a rear-facing seat should withstand, without imposing any load on any other seat in the vehicle, a load equivalent to twenty times the weight of the seat and its occupants applied in the forward direction relative to the vehicle. Seats intended to accommodate more than one occupant should withstand the loads applied by all occupants simultaneously. This requirement should be demonstrated with the occupant load uniformly distributed over the backrest and head restraint of the seat.
The occupant mass to be used to determine the test loads for each category of seat must be:
Category 1 – 68 kgs
Category 2 – 38 kgs
Category 3 – 26 kgs.

Reasearch link:-
[DOC]
COMMERCIAL MANUFACTURE AND INSTALLATION OF ADDITIONAL SEATS
– 8:15am
File Format: Microsoft Word – View as HTML
Rear-Facing Seat Strength. Rear-facing seats and their anchorages must comply with the requirements of the latest edition of ADR 3/. …
www.infrastructure.gov.au/roads/vehicle…/bulletin/…/vsb_05_b.doc