Do these actually save fuel?

UK PROFESSIONAL DRIVERS FORUMS THE UK PROFESSIONAL DRIVERS FORUM (INTERACTIVE)
21

scanny77:

wrighty:
We have two units fitted with them, and they save so much fuel that they haven’t bothered fitting anymore :open_mouth:

Just like teardrop trailers then? They were the thing to have for a while but they seem to have rapidly diminished in numbers these days. Maybe because they didn’t really save all that fuel or possibly because they are totally impractical with a smaller rear door and higher roof (which can mean diverting round low bridges) :unamused:

We have fitted Airtabs to a few rigid bodies but we do not have any conclusive evidence to prove they work. The idea is sound, but if you Google vortex generators, they are far simpler in their design and are used in a different way.

As for Teardrop numbers reducing, it is interesting you should think that. At present, every trailer built for DHL will be Teardrop unless it is impractical to do so. New customers are still investing in Teardrop trailers; the latest being Airbus, H&M, Cherwell Valley, Jacksons Bakery, Orange Box, BMW and Toyota. Older customers continue to order new Teardrops (including Next, TK Maxx, Tradeteam, Marstons, K&N, Ceva etc.).

We agree that the rate of increase in demand has tapered off over the last 12 months or so, possibly due to lower fuel rates; however, current production rates remain high.
At the end of 2015, we had produced 5,301 Teardrops (including Teardrop trailers & Teardrop rigid bodywork).

It’s only a theory, but as the Teardrop has become a mature (launched 2007) and proven product, we don’t do as much marketing so there may be less awareness than there was in the earlier days.

Going forwards, we are now starting to export as larger global operators are catching on to the ‘quirky’ UK success story!

As for fuel saving, we don’t really gather data any more as we already have more than enough to demonstrate how they perform. We openly publish all these results at Teardrop Trailer Case Studies.

22

I can really see McClaren /Ferrari / Lambourghini / and all the Formula 1 race teams fitting these gash looking appendices . :laughing: :laughing: :laughing:
NOT .!

Apparently, ParcelForce had these thingies (vortex generator) officially tested @ Mira research facility.

Can anyone confirm or deny whether ParcelForce took on board the results and had additional Partial /Full Kits fitted to more fleet units / trailers at all :question:
Other than the two test DAF`s which only had partial kit fitted for the testing. :question:

23

Don-Bur:

scanny77:

wrighty:
We have two units fitted with them, and they save so much fuel that they haven’t bothered fitting anymore :open_mouth:

Just like teardrop trailers then? They were the thing to have for a while but they seem to have rapidly diminished in numbers these days. Maybe because they didn’t really save all that fuel or possibly because they are totally impractical with a smaller rear door and higher roof (which can mean diverting round low bridges) :unamused:

We have fitted Airtabs to a few rigid bodies but we do not have any conclusive evidence to prove they work. The idea is sound, but if you Google vortex generators, they are far simpler in their design and are used in a different way.

As for Teardrop numbers reducing, it is interesting you should think that. At present, every trailer built for DHL will be Teardrop unless it is impractical to do so. New customers are still investing in Teardrop trailers; the latest being Airbus, H&M, Cherwell Valley, Jacksons Bakery, Orange Box, BMW and Toyota. Older customers continue to order new Teardrops (including Next, TK Maxx, Tradeteam, Marstons, K&N, Ceva etc.).

We agree that the rate of increase in demand has tapered off over the last 12 months or so, possibly due to lower fuel rates; however, current production rates remain high.
At the end of 2015, we had produced 5,301 Teardrops (including Teardrop trailers & Teardrop rigid bodywork).

It’s only a theory, but as the Teardrop has become a mature (launched 2007) and proven product, we don’t do as much marketing so there may be less awareness than there was in the earlier days.

Going forwards, we are now starting to export as larger global operators are catching on to the ‘quirky’ UK success story!

As for fuel saving, we don’t really gather data any more as we already have more than enough to demonstrate how they perform. We openly publish all these results at Teardrop Trailer Case Studies.

Interesting, what’s the difference roughly in price for let’s say a normal curtainsider trailer and the equivalent but in teardrop form ?

24

You gonna fit em to your wobble box then BB :wink:

25

bald bloke:
Interesting, what’s the difference roughly in price for let’s say a normal curtainsider trailer and the equivalent but in teardrop form ?

Assuming a like-for like specification, you would be looking at circa £500 extra. There are some variances of course depending on rear closure type, XL rating and load restraint options.

Even at just 5% fuel saving (and the average is much higher), based on today’s bulk diesel price of 82.55ppl and circa 80,000 miles per annum, one Teardrop would generate savings of £1,500 per annum so you’re looking at a 4 month payback period.

You’re welcome to use the fuel calculator at CO2 Commercial Vehicle Emissions (Carbon Footprint) Calculator if your operation is any different.

26

nick2008:
You gonna fit em to your wobble box then BB :wink:

Now there’s an idea :exclamation: or convert it to a teardrop :wink:

27

Don-Bur:

bald bloke:
Interesting, what’s the difference roughly in price for let’s say a normal curtainsider trailer and the equivalent but in teardrop form ?

Assuming a like-for like specification, you would be looking at circa £500 extra. There are some variances of course depending on rear closure type, XL rating and load restraint options.

Even at just 5% fuel saving (and the average is much higher), based on today’s bulk diesel price of 82.55ppl and circa 80,000 miles per annum, one Teardrop would generate savings of £1,500 per annum so you’re looking at a 4 month payback period.

You’re welcome to use the fuel calculator at CO2 Commercial Vehicle Emissions (Carbon Footprint) Calculator if your operation is any different.

Ok thanks .

28

Add ons will never work or pay their way.Fuel economy comes from having a good driver in a properly serviced vehicle.

29

alamcculloch:
Add ons will never work or pay their way.Fuel economy comes from having a good driver in a properly serviced vehicle.

We fully agree that driver training and regular servicing is crucial to improved fuel economy. That said, aerodynamic drag accounts for approximately half of fuel consumption at trunking speed and cannot be ignored. The tricky decision making process for Fleet Engineers is investing in proven technology that pays its way without being subject to excessive damage.

Boat-tails, for instance, are proven to generate significant fuel savings but the current designs are vulnerable to damage which could wipe out any fuel savings made over a number of years.

The UK has to continue in the fight to save fuel. Diesel prices are on the up again and we are proud to be part of a nation that has become a global leader for commercial vehicle aerodynamics.

30

Don-bur it’s good to have someone with great in depth knowledge! I’d like to ask a question about your new trailers coming off the line.

They seem to have some kind of anti roll stability thing and activate on roundabouts and bends. I notice that some of the trailers are very sensitive, can this stability control be adjusted to make them less sensitive? Is this anti roll an optional extra or a customer spec?

Also I notice that your new trailers (2015+) the mavis rails are fitted rather low and make connecting air lines awkward. Where as before they where set at the perfect height. Do they come fitted off the line like that or is it a customer specific on the height of the rails? Just wonder why the difference and the thinking behind it?

31

bald bloke:

nick2008:
You gonna fit em to your wobble box then BB :wink:

Now there’s an idea :exclamation: or convert it to a teardrop :wink:

I’ll supply the matches and a gallon of ESSO’S best if you wanna have a flood of tears dropping while watching the tupperwear box melt :grimacing:

32

merc0447:
Don-bur it’s good to have someone with great in depth knowledge! I’d like to ask a question about your new trailers coming off the line.

They seem to have some kind of anti roll stability thing and activate on roundabouts and bends. I notice that some of the trailers are very sensitive, can this stability control be adjusted to make them less sensitive? Is this anti roll an optional extra or a customer spec?

Also I notice that your new trailers (2015+) the mavis rails are fitted rather low and make connecting air lines awkward. Where as before they where set at the perfect height. Do they come fitted off the line like that or is it a customer specific on the height of the rails? Just wonder why the difference and the thinking behind it?

The anti-roll is referred to as RSS and is fitted as standard to everything. We commonly include a Knorr-Bremse TEBS G2 RSP system which senses axle load, lateral acceleration and vehicle speed. First stage intervention is based on a lateral acceleration threshold only which results in low-level auto braking. A brake test pulse is then sent to the wheels to see if they decelerate. If inside wheels decelerate, it assumes they are leaving the road surface and heavy braking auto-applies. If the inner wheels do not decelerate, it assumes all tyres are still in contact with the road and returns to the first stage. Although the settings can be manually altered using the module, it is not advisable as it will “self-learn” anyway to determine centre of gravity. If you believe the trailer is ‘sensitive’, it is possible it has been driven hard in the past so it is using preventative measures.

The height of mavis rails are specified by the customer. It can depend on whether it includes a ground coupling http://www.donbur.co.uk/gb-en/features/trailer-coupling-systems.php (in which case it will be generally lower) or if it has a fridge unit or even if the operator is matching the mounting height on the back of the cab.

Sorry to go ‘off-topic’ here!

33

@Don Bur ,
so are these vortex generators something you would consider incorporating in your build designs for trailers then :question:
Or are we to assume that certain modifications are not suited :question:

34

trux:
@Don Bur ,
so are these vortex generators something you would consider incorporating in your build designs for trailers then :question:
Or are we to assume that certain modifications are not suited :question:

There is no doubt that true vortex generators can improve the quality of airflow where ‘separation’ exists such as the sides and roof of the front bulkhead area. It does so by re-attaching airflow back on to the surface which reduces turbulence and pockets of negative pressure.

Airtabs (as pictured) do not conform to ‘normal’ vortex generator design. They appear more like inverted NACA ducts https://en.wikipedia.org/wiki/NACA_duct but these are low-drag air inlets and are not purely designed to reduce drag.

To date, although we have fitted Airtabs for a few clients, we have not seen any proof yet that they provide any fuel savings.

I’d like to be more positive as they are cheap to fit!

35

Don-Bur:
The height of mavis rails are specified by the customer. It can depend on whether it includes a ground coupling http://www.donbur.co.uk/gb-en/features/trailer-coupling-systems.php (in which case it will be generally lower) or if it has a fridge unit or even if the operator is matching the mounting height on the back of the cab.

Sorry to go ‘off-topic’ here!

There’s been lots of teething-problems with the Mk2 mavis rails where I work. Drivers have been running without the dog-clip in and the brakes automatically come on. Even with the dog-clip in, the brakes still come on, probably because some sensor thinks the rail isn’t secure. Really handy that!

When designing something, truck and trailer manufacturers should cater for the lowest common denominator…the driver. Some drivers will do the job properly but most can’t be arsed and by adding more complexity to a job, even a minor thing such as an extra dog-clip, is a recipe for disaster.

BTW, I’d love to know what field-testing you did for these rails and what types of drivers did you use to test them. Short ones, tall ones, disabled ones?

I’m physically disabled and short and really struggle with these mavis rails, they’ve simply not been designed to be easy to use unfortunately.

36

Are there really many drivers who cant be bothered using the dog clip on the fifth wheel?

37

It’s not the fifth wheel, it’s a dog-clip on the slider rail.

38

I thought I had missed something there when you mentioned a sensor. I’ve never noticed a dog clip on a rail before, is it only on certain brands of trailer, and what is the design reason behind it?

39

well I had never noticed these until I saw an ASDA Volvo yesterday in a site I supply totally covered in them I mean every edge had them on sides top the works - it cant be that cheap with that many on them.

40

ThrustMaster:
There’s been lots of teething-problems with the Mk2 mavis rails where I work. Drivers have been running without the dog-clip in and the brakes automatically come on. Even with the dog-clip in, the brakes still come on, probably because some sensor thinks the rail isn’t secure. Really handy that!

When designing something, truck and trailer manufacturers should cater for the lowest common denominator…the driver. Some drivers will do the job properly but most can’t be arsed and by adding more complexity to a job, even a minor thing such as an extra dog-clip, is a recipe for disaster.

BTW, I’d love to know what field-testing you did for these rails and what types of drivers did you use to test them. Short ones, tall ones, disabled ones?

I’m physically disabled and short and really struggle with these mavis rails, they’ve simply not been designed to be easy to use unfortunately.

I think there’s some good comments here - perhaps worthy of another thread?

Apologies for any confusion her but we use the term ‘Mavis Rail’ for the sliding coupling plate as per the image below:

I think your comments are referring to our ground coupling system which position the plate the side of the trailer so you don’t have to get up on the catwalk?

If so, we accept it’s not perfect. We introduced ground coupling systems some time ago now and it’s an evolving concept. The difficulty for us is the ability to both extend the plate beyond the trailer side and get it to drop significantly enough to couple ‘from chest height’. Obviously, ‘chest height’ alters significantly from driver to driver and we have not able (yet) to devise a system that caters for all heights and abilities.

As for the sensor, this is now only specified with one client. All other current designs do not include this brake interlock and we simply provide a warning light on the O/S front bulkhead. The sensor (on the interlock systems only) has also been modified from an infra-red to a magnetic proximity design to reduce false readings.