Tag Archives: technology

I Feel The Need….. The Need for Speed!

The sun streamed through the slightly dusty windows of the Alton branch of Costa Coffee, as I sat enjoying my coffee, catching up with the news, both digital and conventional.

 

An article caught my eye about road safety, so, having had my curiosity piqued, I conducted some research which I found very interesting, and in the spirit of friendship and understanding, I offer my thought to you, gentle reader.

 

Speed Cameras. Love them or loathe them, they do serve their purpose, which is reducing speed, and increasing safety. However, adherence to the speed limit isn’t the sole factor that a driver is monitoring, particularly when driving in heavy traffic, or demanding road conditions. Distraction management is not a skill that is taught during driving lessons, and maybe it should be.

 

It would appear that most Police Authorities are aware of this weakness, and allow for a tolerance in speed keeping, to ensure that motorists are not penalised unfairly for a momentary breach of the speed limit.

 

Most police forces in the UK have confirmed that they allow for a 10% error plus a 2 mph additional tolerance to account for minor lapses in driver speed control. This is an agreed standard set by the National Police Chief’s Council.

 

As far as I am aware, this margin was originally put in place to account for the inaccuracies of early speedometers, which were cable driven from either a gearbox on a road wheel, or from the vehicle transmission gearbox. I have also heard anecdotally, that the additional 2 mph was to account for what we could call distraction error.

 

A recent Freedom of Information request made by Auto Express© (www.autoexpress.co.uk) to UK police forces confirmed that 22 constabularies adhere to the guidelines, and cameras are calibrated to trigger at the posted speed limit plus 10% + 2 mph (i.e. in a 30 mph limit, a camera will trigger at 35 mph, in a 40 zone at 46 mph etc)

 

The remaining eight constabularies declined to offer full details of the trigger tolerances, which is a shame, but understandable.

 

According to a study conducted by the London School of Economics and Political Science, [1] speed enforcement cameras reduced accidents by between 17 to 39 per cent, and reduced fatalities by between 58 to 68 per cent[2], so they are definitely an effective measure in improving safety.

 

Interestingly, speeding accounted for 60 per cent of all fatal accidents in the UK in 2015.

 

However, whilst the cameras reduced accidents within 500 metres of the site, accidents outside the camera zone increased, as drivers either braked suddenly to ensure they were in compliance with the limit, or accelerated heavily once outside the camera’s operational range.

 

As a result of this behaviour, more and more speed limits are now enforced with average speed cameras, which ensure compliance over a greater distance, and without the related dangers of braking and accelerating in the locality of the speed camera site. This works very well, as I can testify to.

 

One of my regular routes takes me up the A3 towards London. Just south of Guildford, the national 70 mph limit drops to 50 mph, in the area known locally as Wooden Bridge. Up until recently, it was almost impossible to maintain 50 mph in safety due to aggressive tailgaters, dangerous filtering and regular high speed lane changes and sudden lane changes.

 

A few weeks ago, Average Speed Enforcement was activated, and as a result, most drivers now comply with the 50 mph limit, and aggressive tailgating is negated by the need to maintain 50 mph.

 

Human behaviour, being what it is, means that wherever it appears safe to breach the rules, then a driver will consciously break the limit. I admit that on an empty motorway, I often take a calculated risk and drive at 80 or 90. I have done so on a number of occasions, when my experience and perception indicates to me that it is safe to do so. I say that with the benefit of 42 years of driving experience, both on motorcycles and in cars.

 

It often appears that the authorities are willing to reduce speeds when appropriate, but not to increase speeds when the conditions warrant it.

 

Across the EU, they take a sensible and pragmatic approach. In France for example, I have seen a limit of 130 kph (81mph) with a further sign reducing the limit to 110 kph (68 mph) in rain.  Across the Netherlands, the Autoroute limit is 130 kph as well, so 10 mph faster than the maximum speed limit in the UK. So much for EU unity!

 

As it appears that drivers are incapable or unwilling to abide by speed limits, which to be fair, are generally there for the safety of all road users, the EU is now is now mandating that all vehicles manufactured after 2022 will be fitted with Intelligent Speed Adaption (ISA).

 

There is currently a lot of mis-information about what is perceived as external speed control. ISA is designed to complement the driver’s speed keeping discipline, and will intervene should the speed limit be exceeded.

 

ISA is an onboard system that tracks the vehicle’s position by GPS, and compares the co-ordinates with a speed limit database. The system then continuously monitors the vehicles speed.

 

ISA will be designed to offer three modes of operation.

 

At the most basic level, should ISA detect a breach of the posted limit, an audio/visual warning will be generated to alert the driver. This is referred to as an “Open” system. This is an advisory system only, and the driver may choose to ignore the system-generated warnings.

 

Should the authorities decide that the system should be more robust in its levels of intervention, then either a “Half Open” or “Closed” system will be mandated.

 

The Half Open system will be designed to provide force-feedback through the accelerator pedal should the posted limit be exceeded, thus giving the driver not only an audio/visual warning, but a sensory input that actively resists the foot pressure delivered to the accelerator. The driver would then have to consciously make an effort to overcome the feedback pressure. This enables a driver to breach a posted limit in the event that an emergency condition dictates it.

 

Lastly, is the “Closed” system, which actively prevents the speed limit being exceeded, and gives the driver no means of intervention

 

There are obviously drawbacks to the ISA as a system.

 

Firstly, there is a risk that further automation of the driver’s interactive functions will reduce the level of awareness and involvement, potentially leading to a reduction in attention to road and traffic conditions. Loss of awareness is highly dangerous, and could in itself lead to further accidents.

 

Secondly, once a driver has accepted the use of such a system, there may be a tendency to become over confident, with a perception of invulnerability as the system effectively manages maximum speed. However, as the system only monitors compliance with the maximum speed, the driver needs to remain involved and “in the loop” as conditions may dictate a much lower speed for safety.

 

Some drivers may also become frustrated at the system holding them at what they consider to be a speed that is too low for safety, especially where speed limits have been set arbitrarily rather than as a result of evidence based decisions. This may result in risk based behaviour.

 

 

 

So, vehicles are becoming much more automated, and much work needs to be done on developing that man-machine interface.

 

I am so glad that I enjoyed driving as a young man during the years when there were no speed cameras. As a country teenager, I took my chances with getting caught by the police whilst rocketing around the lanes of Sussex at lunatic speeds. I was lucky that I enjoyed this without sustaining a crash, injuring or killing anyone else, and without receiving any driving bans.

 

This is a privilege that is denied younger drivers now.

 

Brave new world?

 

 

You decide.

 

 

Mark Charlwood© May 2019

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[1] Figures from 1992 – 2016 Cheng Keat Tang PhD

[2] Within 500 metres from the camera site

Electric Taxi – A New Brand New Era in Green Aviation Practice

.Ask anyone in the street about pollution and noise, and most folk will immediately talk about the road transport industry, or, if like me, they live near a major airport, then they would probably refer to the airlines.

Over the last fifty years, air travel has opened up a whole new dimension to travellers. Whether travelling on business, or taking the family away, air travel enables people to reach some of the remotest parts of our planet.

During the early and mid parts of the 20th century, air travel was expensive, and only those travellers with access to a large amount of disposable wealth could afford to fly. 

This was in part caused by the relative lack of supporting infrastructure, but the size of aircraft was also a limiting factor.

The biggest direct operating cost for any airline is that of fuel, and the current smaller aeroplanes were unable to offer the economies of scale necessary to place flying within the reach of the average man. 

To put this into perspective, in the early 1960s, the workhorse of the sky was the Boeing B707, which had a seating capacity of about 140. 

On the 22nd January 1970 Pan Am introduced the very first Boeing 747-100 into service. This aeroplane changed the face of aviation forever.  With its massive seating capacity, of more than double that of the 707, the costs for air travel fell dramatically, and even the poorest backpacker could save enough money to make a transatlantic or transpacific flight.

Over the years, developments of the 747 have continued, and as an example, a British Airways 747-400 will carry 345 passengers over vast distances.

But there are always other factors.  The 1973 oil crisis made fuel costs escalate rapidly, and a number of airlines went out of business. Those that survived recognised the need for newer far more fuel efficient aircraft.

Aircraft manufacturers rose to the challenge, and many new aeroplane were developed, constructed from much lighter materials, including polymers and carbon fibre materials. 

Engine manufacturers have developed cleaner, quieter and far more fuel efficient engines, and new software driven control systems enable aircraft to fly far higher, out of the worst of the weather, and at altitudes where engines are even more frugal.

Sadly, this is still not enough.  The global energy crisis continues, and international concern with  climate change is driving fuel costs upwards.

Airlines are looking to save costs wherever they can.  Most airlines will defer operating the Auxiliary Power Unit (APU) until shortly before boarding, and some airlines have established a policy that requires aircraft to be taxied with one engine shut down.

The economics of this are sound, and saving may be made.

According to Airbus Industrie an Airbus A320 fitted with CFM56 engines will burn 250kg of fuel conducting a twenty minute average taxi time. A single engine taxi of the same duration will burn a reduced amount of 190kg.

Using IATA fuel data, jet fuel (Jet A-1) costs £0.3613 per kilo so a single engine taxi will cost the operator £68.65.  Two engines £72.26. This is doubled effectively, as the aircraft also has to taxi in after landing, which again, will take an average of twenty minutes.

Throughout 2014 fuel prices fell by an average of 42.8%, so it is reasonable to assume that they could rise again by the same amount, giving taxi costs of between £98.03 and ££103.19. 

A very simple costing taking into account British Airways fleet of 105 Airbuses, assumes that each aircraft flies 5 sectors a day (5×2 taxies = 10 x 20 minutes x 105) that’s a massive 350 hours of taxiing. 

350 hours x 60 = 21,000 minutes @ 12.5kg/min = 262,500 kg = 262.50 tonnes!

Now the figures look very different. In the above example, fuel currently costs £361.25 per tonne.  

£94,828 to just taxi around the airfield. Remember this is just a single days operation for one short haul fleet. 

Operators will be very keen to both minimise taxi times, and to reduce costs as much as possible during taxiing.

Airbus have been working on a new self propelled taxying system for the Airbus A320 series, known as eTaxi.

This system utilises a powerful air cooled electric motor that drives the main landing gear wheels via a self contained gearbox.

Powered is provided by the APU generator. The eTaxi motor has sufficient power and torque to enable the aircraft to be reversed off the parking stand, and then taxied to the holding point for the departure runway. At this point, the engines may be started.

Naturally, current procedures and checklists would have to be amended and modified to reflect the use of eTaxi to ensure continuation of current ground movement safety.

The eTaxi system offers many benefits.  Airbus’s own studies have shown that even greater fuel savings may be made than by using single engine taxying. 

Using the AP/eTaxi and a single engine for taxying equates to a fuel burn of 140kg, and full electric taxying only 40kg for the same 20 minute taxy.  

 Using the same fleet data as before, the savings are considerable. 

350 hours x 60 = 21,000 minutes @ 2kg/min = kg = 42.00 tonnes!

With fuel in our example currently costing £361.25 per tonne, 42 tonnes costs £15,172.50, a massive daily saving of £79,655.50!

Naturally,  there is a weight penalty for the eTaxi equipment, consisting of motor, gearbox, wiring harness and software and control equipment, but Airbus Industrie quotes this as being about an extra 400kg, and over a 500nm sector, this would require an additional fuel burn of 16kg.

Overall the use of eTaxi with both engines shut down, and including a 5 minute engine warm up and a 3 minute engine cool down, will offer a trip fuel saving of about 3% on a typical A320 sector of 700nm. 

So, the airline accountants will be happy with the considerable direct financial savings.  However, there are many other associated benefits by using an eTaxi. 

During taxying operations, aircraft frequently have to stop, accelerate, turn and hold in position.  This places wear on the brakes, and incurs fuel penalties every time that the thrust levers are opened to recommence taxying.  

As eTaxi is a direct drive system, the normal wheel brakes become redundant, the braking being delivered through the gearbox itself.  

 Environmentally, eTaxi makes a lot of sense.  The use of clean electricity for ground movements will significantly reduce the amount of NOx (Nitrogen Oxides such as Nitric Oxide and Nitrogen Dioxide) and CO (Carbon Monoxide) found in the local atmosphere.  Noise levels will also be significantly reduced. 

An additional benefit is a reduced exposure to the risk of the engine ingesting foreign objects, and extending the time between mandated engine inspections and checks.  

Bearing in mind that the biggest cost for an airline is fuel. Last year British Airways spent £3.5 Billion pounds on fuel. Most large national carriers will be spending about the same.  The figures are almost too large to contemplate. 

It would appear then, that any additional costs in retrofitting such devices to an existing fleet will pay for itself many times over, and any airline that specifies new deliveries without this option are potentially wasting millions.

Facts from Airbus Industrie publication FAST 51

Fuel costs from IATA Fuel cost analysis 2015

BA fleet data from http://www.ba.com

BA Fuel costs data from http://www.iag.com

Mark Charlwood©2015. Mark Charlwood is the owner of the intellectual property rights to this work. Unauthorised use is not permitted. If you want to use this article please contact me for permission. Thank you.