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Nils Christensen (1921 – 2017)

Hawaii Mars C-FLYL a Martin JRM Mars cargo transport seaplane, converted to a water bomber in the early 1960s by Nils Christensen while working with Fairey Aviation. This shows the machine moored on Sproat Lake, Vancouver Island, British Columbia on 2006-10-31. Photo: Alex Juorio

Nils Christensen was a Norwegian-Canadian entrepreneur who founded the Canadian aerospace manufacturing firm, Viking Air Ltd. He was born 1921-08-21 in Høvik, Bærum (adjacent to Oslo), Norway. At the age of five he claims to have witnessed the airship Norge heading off on an exploration trip to the North Pole.

After finishing his training as an apprentice mechanic, Christensen worked in the merchant marine until 1942 when he enlisted in the Royal Norwegian Air Force (in exile) in New York City, USA. He was trained as an aircraft mechanic at Little Norway, Lille Norge, the Norwegian Air Force Training Camp, Flyvåpnenes Treningsleir, at Muskoka airfield, near Gravenhurst, Ontario, Canada.

After completing his training in 1943, he was posted to the 333 (Norwegian) Squadron RAF based at Leuchars, Fife, Scotland, under control of the RAF Coastal Command, Christensen acted initially as an aircraft mechanic for de Havilland built Mosquito aircraft.

In 1946, Christensen attended Engine Instructors’ School in England, then he instructed on engines and aircraft for the Royal Norwegian Air Force. In 1947, he left the Air Force, and soon after obtained his Norwegian Aircraft Mechanic’s license. He began civilian work as a flight engineer and a station engineer for Braathens South-American & Far East (SAFE) Airtransport, flying and maintaining Douglas DC-3 and DC-4 aircraft. He was transferred to Amsterdam, Holland by Braathens.

In 1951, Christensen moved to Toronto, Ontario, Canada, working for de Havilland Canada, converting Lancaster bombers into air-sea rescue machines. In 1952 he became chief of maintenance at Sault Airways, a bush plane operation, where he serviced float and ski aircraft including Norseman and Cessna. He also earned his Canadian Aircraft Maintenance Engineer (AME) license.

In 1956, Christensen moved to Sidney, British Columbia, Canada, where he became chief of maintenance at the Victoria Flying Club. In 1959 he joined Forest Industries Flying Tankers (FIFT), as a flight engineer and superintendent of maintenance on the giant Martin JRM Mars water bombers. These, the largest flying boats ever built, were initially developed for the US Navy in WWII as a cargo transport seaplane, Seven were built. Three were lost by 1950. The remaining four were purchased from the US Navy by FIFT in 1959. Christensen obtained his Flight Engineer License in 1960, and began working with Fairey Aviation converting the Mars to firefighting water bombers, that operated out of Sproat Lake, Vancouver Island, British Columbia.

In 1961 one of the converted Mars crashed killing all four crew members, then in 1962, the other completed plane was destroyed by Typhoon Freda at the Victoria Airport. The conversion of the remaining two Mars aircraft was completed in 1963. These water bombers were operated by FIFT until 2007 when they were purchased and operated by Coulson Flying Tankers, until their retirement in 2016. A weblog post on these water bombers is a work in progress.

In 1965, Christensen left FIFT and joined Fairey Aviation, recently purchased by IMP Group International after the collapse of the British mother company, servicing a variety of aircraft. In 1967, he became foreman of McKinnon Enterprises, an aircraft parts and modification facility in Sidney, where he was responsible for rebuilding/ converting three amphibian Grumman Goose aircraft to turbine power, and upgrading four Grumman Widgeons.

In 1970, Christensen bought Victoria Flying Services and its 11 aircraft. When McKinnon Enterprises closed in 1970, Christensen also bought all of its equipment and started his own company, Viking Air Ltd., that focused on overhaul, maintenance and conversions of various small aircraft, especially flying boats including the Grumman Goose, Widgeon, Mallard and Albatross. When Viking Air started it had two people on the floor and one in the office. By 1979, it had 25 people in the main shop, and six in Viking Shell, a fuel dealership and pilot’s lounge.

In 1983, Viking Air moved into manufacturing. After 10 years of negotiations with de Havilland Canada, Viking Air was selected as their sole parts producer and distributor for Beaver and Otter aircraft. Christensen sold Viking Air Ltd. and retired as President in 1987. Viking Air had grown from three employees to 50 at the time of Christensen’s retirement.

In 1993, Christensen and his wife moved from Sidney to Salt Spring Island, British Columbia where they lived for 24 years. In 2017-03, they moved to Abbotsford, British Columbia to be near family. Nils Christensen died in Abbotsford on 2017-08-06. In 2018-10, his ashes were interred at the 800 year-old Haslum Church and Cemetery in Bærum, Norway.

This weblog post concludes a short series about de Havilland Canada related topics. Since this post primarily deals with Christensen in his role as an aircraft mechanic turned manufacturer, and not his other contributions, people interested in other details of his life, may want to read more about him in Wikipedia.

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Twin Otter: A tidbit

First flight of the new Series 400 Twin Otter, manufactured by Viking Air (the current type certificate holder). This airplane is the technical demonstrator C-FDHT. Photo taken at YYJ Victoria International Airport, 2008-10-01 by paneuropean at Wikipedia.

The Twin Otter is a popular and successful commercial aircraft, with 985 units built, as this weblog post goes to press. It is praised for its rugged construction and STOL (Short take Off and Landing) characteristics. Its price in 2017, was US$ 6.5 million.

Development of the Twin Otter started in 1964-01, when de Havilland Canada commenced work to modify the DHC-3 single-engined Otter design into a twin-engined turboprop STOL commuter airliner and utility transport, designated DHC-6. This involved lengthening the wings, and redesigning the rear fuselage, tail, and nose. Seating was increased to a maximum of 18.

Construction of a prototype began in 1964-11, which was first flown on 1965-05-20. There have been several production series, most notably the 100, 200 (from 1968-04) and 300 (from 1969). De Havilland ceased production of the Twin Otter in late 1988 after producing 844 aircraft.

Fortunately, after Series 300 production ended, the remaining tooling was purchased by Viking Air of Victoria, British Columbia, allowing it to manufactures replacement parts for all of the out-of-production de Havilland Canada aircraft.

On 2006-07-17, Viking Air announced its intention to offer a Series 400 Twin Otter. On 2007-04-02, Viking announced it had received 27 orders and options, and was restarting production of the Twin Otter. In 2007-11 a new assembly plant was established in Calgary, Alberta. The design has been modernized.

As of 2019-12, The 141 Series 400 Twin Otters have been made. Currently, 38% are operated as regional airliners, 31% in military aviation or special missions, 26% in industrial support and 5% in private air charter. About 70% use regular landing gear wheels, 18% are configured as straight or amphibious floatplanes, 10% use tundra tires and 2% use wheel skis.

In Norway, Widerøes Flyveselskap A / S became the major civil buyer of Twin Otters. In the late 1960s there was a large-scale development of small airports in Northern Norway and on the coast of Western Norway. Most of these airports had 800 meters long runways, suitable for Twin Otters, but almost nothing else. Widerøe bought their first Twin Otter in 1968, LN-LNM (s / n 127). In total, Widerøe bought 12 Twin Otters directly from the factory, besides 2 that were purchased used.

The Twin Otter showed outstanding reliability, and remained in service until 2000 on certain routes. Widerøe was, at one time, the world’s largest operator of Twin Otters. During one period of its tenure in Norway, the Twin Otter fleet achieved over 96,000 cycles (take-off, flight, and landing) per year.

Further information about the Twin Otter in Norway, but written in Norwegian, can be found here.

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de Havilland Canada: A tidbit

A de Havilland Canada DHC-7-100 Dash 7 LN-WFE in Widerøe livery at Hammerfest Airport 1987-07-04. The author used Dash 7s to commute between Bodø and Tromsø between 1986 and 1988. Photo: Udo K. Haafke

De Havilland was started in 1920 by Geoffrey de Havilland (1882 – 1965) at Stag Lane Aerodrome, Edgware on the outskirts of north London. Operations were later moved to Hatfield in Hertfordshire. De Havilland Canada started life as a subsidiary in 1928, for the purpose of making assorted versions of Moths, variously described as light aircraft/ sports planes/ military trainers. During the second world war, de Havilland Canada was nationalized, by the Canadian government. It remained a crown corporation until the 1980s, when the government privatized it, then sold it to Boeing, in 1986.

While the British parent company is especially noted for the versatile design of its DH.98 Mosquito warplane, made largely of wood with 7 781 produced between 1940 and 1950, and the DH 106 Comet, the world’s first jet airliner, with 114 produced between 1949 and 1964, de Havilland Canada innovated some unique designs, especially suited for flying in the “bush”. These are:

TypePurposeCapacityfirst flightproduction#
DHC-1
Chipmunk		Trainer219461947 – 19561 283
DHC-2
Beaver		Bush1 + 719471947 – 19671 657
DHC-3
Otter		STOL Bush1 + 1119511953 – 1967466
DHC-4
Caribou		STOL Cargo3 + 3219581961 –
late 1960s		307
DHC-5
Buffalo		STOL Cargo3 + 4119611965; 1974122
DHC-6
Twin Otter		STOL Utility2 + 19651966 – 1988
2008 – 		985
DHC-7
Dash 7		STOL Regional2 + 35 – 5419751978 – 1988113
DHC-8
Dash 8		Regional2 + 37 – 9019831984 –1 249

Despite Canadian government claims to have guarantees to prevent Boeing discontinuing product lines, both the Twin Otter and Dash 7 were discontinued, with their jigs and specialised manufacturing equipment destroyed. DHC was eventually acquired by Bombardier Aerospace in 1992, and integrated into the Bombardier group of companies.

On February 24, 2006, Viking purchased the type certificates from Bombardier Aerospace for all the out-of-production de Havilland Canada aircraft (DHC-1 through DHC-7). The ownership of the certificates gave Viking the exclusive right to manufacture new aircraft.

In November 2018, Viking Air’s holding company, Longview Aviation Capital, announced the acquisition of the Q400 program – a modernized version of the Dash 8, where the Q (for quiet) indicates that planes are fitted with active noise control systems – along with the rights to the de Havilland name and trademark. The deal, which closed on 2019-06-03 following regulatory approval, brought the entire de Havilland product line under De Havilland Aircraft of Canada Limited.

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ePlane: A tidbit

Harbour Air DHC-2 Beaver floatplane in Richmond, British Columbia, powered by an electric magniX magni500 propulsion system. Photo: Harbour Air.

On 2019-12-10 Harbour Air successfully flew the world’s first all-electric commercial aircraft, the ePlane, a six-passenger DHC-2 de Havilland Canada Beaver on floats, with call sign C-FJOS and production number 1030 of the 1 692 DHC Beavers ever built. Originally delivered with a piston ICE engine on 1957-03-01, it spent most of its operational life based in Prince Rupert, British Columbia.

This aircraft, with yellow and blue livery, is now powered by a 560 kW magni500 propulsion system. Its first electric propulsion flight started and ended on the Fraser River at Harbour Air floatplane terminal in Richmond, British Columbia at YVR South, part of Vancouver International Airport.

Richmond is the home base of Harbour Air, North America’s largest floatplane airline. It specializes in routes between Vancouver, Nanaimo, Victoria, Sechelt, Comox, Whistler and the Gulf Islands. There are also flights between downtown Vancouver and downtown Seattle. They also have a European subsidiary in Malta.

Harbour Air has a history of green operations, that is deeper than a typical greenwash. In 2007, it became the first airline in North America to achieve complete carbon neutrality in both flight services and corporate operations. It has announced its intention to build the world’s first completely electric commercial floatplane fleet, but because of certification requirements, including testing, it will have to wait until about the beginning of 2022 before this can start. The company is regarded as one of the best managed in Canada, and has won awards for this.

The Harbour Air fleet consists primarily of de Havilland Canada floatplanes: 14 DHC-2 Beavers (5 – 6 passengers), 21 DHC-3-T(urbo) Otters (10 – 14 passengers) and 3 DHC-6 Twin Otters (18 passengers).

In March 2019, Harbour Air announced a partnership with magniX to electrify the entire Harbour Air fleet over the long term. Harbour Air has noted that its initial electric-powered commercial flights will be on routes of under 30 minutes’ duration. The DHC-2 Beaver serves as the test prototype for the magniX motor, energy storage, and control systems.

MagniX is an Australian electric motor manufacturer for electric aircraft, wholly owned by Singapore investor Clermont Group. Its engineering headquarters is located on the Gold Coast, Queensland, Australia. Its global headquarters and US development centre is located in Redmond, Washington, near Seattle.

One of the main advantages of an electric motor in an aircraft is full torque at low RPM. In addition, the mechanics are simpler, reducing the number of parts as well as weight. For example, a propeller can be attached directly to the motor without a reduction gear.

The magni500 was unveiled at the Paris Air Show in June, 2019. It provides 560 kW, and 2800 Nm of torque. It weighs 135 kg. The smaller magni250 motor provides 280 kW, and 1400 Nm of torque. It weighs 72 kg. Both types of motors rotate at between 1900 and 3000 RPM, and offer 93% power conversion efficiency. Both motors can be regarded as high-power-density electric propulsion systems that provides a clean and efficient way to power airplanes. The company also makes a magniDrive 170 kW power electronics system used to run both the magni250 and magni500.

Sources: Beaver Tails ; Harbour Air ; Magnix ; Wikipedia – Harbour Air Seaplanes & Magnix .

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Cybertruck update: A tidbit

Find the Cybertruck! Photo: Found on Electrek.co

There has been a lot of media content produced about the Tesla Cybertruck. Here are some comments.

  1. Alasdair McLellan noted that the window damage to the Cybertruck was, if not deliberate, at least expected. How else could Musk ensure that every newspaper, magazine, blog and any other source on or off the web, publish a photo of the Cybertruck, so that everyone in the universe knows what a Cybertruck looks like?
  2. Adrián Esper Cárdenas, Mayor of Ciudad Valles, San Luis Potosí, Mexico, saw the electric truck as having great potential as a local police and municipal vehicle. He reserved 15 Tesla Cybertrucks!
  3. Mike Gastin described the Cybertruck as a branding masterstroke. At 6:05 into the video he says (and writes) that Tesla is Delivering the Future – Today!
  4. Robert Llewellyn’s recent edition of Fully Charged News is full of the usual rants, this time about the Cybertruck as well as the Mustang Mach-E.
  5. Jameson Dow, writing in Electrek, is claiming that the Cybertruck is popular in markets where other Tesla products have failed to capture interest. “The Tesla Cybertruck is the first time we’ve gotten a chance to compare data between a sedan launch and a pickup launch from the same company. And it turns out that, despite Tesla’s brand appeal on the coasts, the Cybertruck is breaking new ground and doing quite well in the “heartland” – where pickup trucks are traditionally more popular than sedans.”
  6. Here is a reference to Matt Ferrell’s Undecided, who asks: Why do we hate something viscerally at first, and then come to love it a little while later?
  7. There are even more details at Design Prototype Test. It provides some engineering concepts missing in other sources, but there are also misunderstandings. For example, EVs do not have engines, they have motors.

A major challenge with many YouTube videos/ channels is that they are one-person operations, without sufficient quality control. Rants are very easy and cheap to produce. Quality, fact-based information is a little more difficult and expensive to produce. They also requires thought, in addition to emotion.

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Tesla Cybertruck: A tidbit

Visitors to the Tesla Cybertruck webpage are greeted with an elongated version of this photo of the Cybertruck ptototype. (Photo: Tesla)

The term pickup is of unknown origin, but was first used by Studebaker in 1913 and by the 1930s had become a generic term for a light-duty truck having an enclosed cab and an open cargo area with low sides and tailgate. In North America, the pickup is mostly used as a passenger car and accounts for about 18% of total American vehicle sales, in part because it benefits from lower fuel and emission control regulations, and tax breaks from the IRS. Full-sized pickups and SUVs account for more than two-thirds of their global pretax earnings of GM, Ford and Fiat-Chrysler, because of their high prices and profit margins.

Elon Musk unveiled Tesla’s first pickup, the Cybertruck, in Los Angeles 2019-11-21. It is battery-powered. Tesla’s stated goal is to displace a large portion of fossil fueled light trucks sold.

Cybertruck’s styling is anything but charming, and many commented that the presentation setting, in both time and place. was that of the original Blade Runner. However, the Cybertruck has many positive characteristics including a durable exterior shell made of a light-weight titanium alloy, for passenger protection. It is also claimed that every component is designed for strength and endurance. These are important considerations in a truck.

Specifications, both estimated and revealed: Vehicle mass = 2 700 kg/ 6 000 lbs; payload = 1 600 kg/ 3 500 lbs; power = 570 kW/ 775 HP; storage space = 2 830 litres/ 100 ft3 ; vault aka bed length = 2 meters/ 6.5 feet; ground clearance = up to 410 mm/ 16 “; approach angle = 35 degrees; departure angle = 28 degrees; seating = 6 in two rows.

Characteristics that vary, depending on the model, are included in the table below.

1- motor 2-motor3-motor
Drive wheelsRWDAWDAWD
Range km/ miles400/ 250500/ 300 800 / 500
0 -100 kph; 0 – 60 mph in s< 6.5< 4.5< 2.9
Top speed kph/ mph177/ 110193/ 120209/ 130
Towing capacity kg/ lb3 400/ 7 5004 500/ 10 0006 350/ 14 000
Price (to closest US$ 1 000)40 00050 00070 000

Compressed air is an important feature of the Cybertruck. It allows for a self-levelling suspension which compensates for variable load. In addition it provides power for pneumatic tools. On-board power inverters supply both 110 and 220-Volt electricity, for electrically powered tools.

At the presentation, Tesla’s armoured glass failed to work as intended, when a steel ball thrown by design chief Franz von Holzhausen shattered two windows in two attempts. The presentation ended with a Tesla Cyberquad electric ATV being loaded onto the truck vault, using built-in tailgate ramps. The Cyberquad was then plugged into the Cybertruck’s onboard power outlet, to charge it.

My hope is that many people currently buying Ford F-150s, Chevrolet Silverados, Rams and other ICE pickups, will be encouraged to buy either a Cybertruck, or a more conventional looking Rivian R1T, or other suitable electric vehicles. Personally, I am not part of the pickup culture. My Brenderup 4310S utility trailer meets almost all of my freight transport needs, and should do so for the rest of my life.

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The Charm of Endurance

The Workhorse W-15 Hero, renamed the Lordstown Motors Endurance. Photo: Workhorse Group.

In 1998, Workhorse Custom Chassis was founded in Cincinnati, Ohio to take over production of General Motors’ P30/P32 series stepvan and motorhome chassis. By 2005, the company was taken over by Navistar International, its supplier of diesel engines. Navistar then closed the plant in 2012.

AMP Electric Vehicles bought the company in 2015, and changed its name to Workhorse Group Incorporated, scattering attention on electrically and ICE powered delivery vans, buses and recreational vehicles.

In 2016, Workhorse introduced a W-15 Hero prototype, an all-wheel drive plug-in pickup. It used custom battery packs, to provide power to an electric-drive, with a range oft 80 miles/ 130 km. These batteries were housed underneath the vehicle to save space and provide more payload capacity. Confusingly, a BMW three-cylinder generator/ range extender was also provided, making this a hybrid ICE vehicle, rather than a pure battery electric. The vehicle was be built with four motors — one for each wheel — to deliver all-wheel drive. It also had outlets to run power tools off the vehicle battery.

In 2018, Workhorse scattered attention again, by announcing Surefly, its two-seat gasoline/ electric hybrid eVTOL (vertical takeoff and landling) octocopter.

On 2019-11-07, the newly constituted Lordstown Motors Corporation purchased the 576 000 square meter Lordstown Ohio assembly plant from General Motors. This plant originally opened in 1966. Confusingly, some reports say Workhorse Group has a 10% stake in this plant, others state that it has no financial involvement.

The plant has been a political liability for GM since its 2018 announcement that it would not use the facilities. This became an immediate political liability for Donald Trump, who earlier had discouraged supporters from selling their homes in Lordstown because of all the jobs he would bring back to the area

Steve Burns, previous CEO of Workhorse, and current CEO of Lordstown Motors, is fundraising to convert the plant so it can manufacture electric vehicles. What used to be called a Workhorse W-15, is now being called a Lordstown Motors Endurance, targeting pickup truck fleet buyers.

Meanwhile, Workhorse Group is bidding on a contract to make plug-in mail trucks for the U.S. Postal Service. Even if Workhorse wins the postal contract, it is unclear if the Lordstown plant would build those vehicles. Lordstown Motors does have an agreement to transfer the 6 000 existing pre-orders for the W-15/ Endurance from Workhorse Group to Lordstown Motors for production.

Burns has stated that Workhorse and Lordstown Motors share intellectual property related to electric-drive systems.

Production of the W-15/ Endurance is dependent on successful funding. If sufficient funds were raised, Burns said he would work with the UAW (United Auto Workers Union) to hire staff who didn’t transfer to other plants. Burns wants experienced vehicle assemblers to build the trucks.

Lordstown Motors has the money to buy the plant and work on the vehicle, but needs more money to continue development, conduct crash and safety testing, get the truck approved for sale and to retool the factory.

Lordstown Motors is not the only electric pickup attracting attention. The Rivian R1T pickup is possibly the top contender, is fully electric, has an exciting design that it shares in part with its R1S SUV sister, a large fan base willing and able to purchase vehicles, financing under control, and production facilities secured in Normal, Illinois. Ford has also announced its own fully electric version of its F-150 pickup. Yet, the pickup everyone is wanting to learn about is the Tesla Cybertruck, to be unveiled in Los Angeles, 2019-11-21. Which is why anything about the Workhorse W-15 Hero/ Lordstown Motors Endurance had to be pushed out now.

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The Charm of a Uniti

The production model Uniti One, available in three gray colours. (Photo: Uniti)

Uniti began life as an open innovation project at Lund University in 2015, then emerged as a Swedish electric vehicle startup in 2016. It is developing an advanced city car. What first attracted my attention, was the replacement of the steering wheel with a joy-stick. Most of the mechanical system appeared equally innovative, and claimed to be sustainable, whatever that means.

Prototype development was funded through an equity-crowdfunding campaign on the Swedish platform FundedByMe, with 570 investors contributing €1,227,990.

The design mandate of the Uniti One seems to be in a state of flux. At one time, it was a relatively unsafe L7e quadricycle. Now, thankfully, it is being lauched as a M1 vehicle requiring crash testing, and more safety equipment. Other details, such as seating arrangements have also been subject to change. It was a side by side 2 seater, before it became one with one person sitting behind another. Now it is launching as a 3 seater, with a driver in the middle in front, with space for two passengers behind. Trunk space is adequate to hold a packed lunch and a charging cable, at 155 litres.

With a 50 kW electric motor and 62 Nm of torque, and a mass under 600 kg, the Uniti One can reach 100 km/h in less than 10 seconds. It has a computer controlled top speed of 120 km/h.

The Uniti One comes with an electrochromatic panoramic roof that darkens automatically to keep the car cool when parked in direct sunlight. Its virtual sun visor darkens the top of the windshield when the sun is in the drivers eyes.

An Android operating system controls the infotainment system and most of the standard features of the car. Voice commands can be issued. Its systems are regularly updated over the air.

A high strength safety cage surrounds the driver and passengers keeps interior deformation to a minimum, in the event of a collision. Other standard safety equipment include driver’s airbag, anti-lock braking, electronic stability control and a tire pressure monitoring system. The Intel MobilEye 6 collision avoidance system provides forward collision and lane departure warnings, speed limit indicator, and warning for potential collisions with pedestrians or bicycles and their riders, in real time.

In its current state, what appeals most about the Uniti One is that much of the equipment is optional, which means that people declining options can end up with a lower cost vehicle. Currently, the base model costs about €18 000, before subsidies. The only options I would insist on would be the Intel Mobileye 6 collision avoidance system (€ 700), winter tires (€ 400) and possibly air conditioning (€ 300). This is not a highway vehicle, so a 150 km range with a standard 12 kWh battery and a slow 3.2 kW charger seem adequate. It seems wasteful to spend €2 800 each on a 24 kWh battery and a 22 kW charger.

In terms of a computer vehicle transporting one person and a lunch bag in an urban environment, this is probably a good choice except, in urban environments there is public transport, which would be a better choice.

That said, my greatest disappointment with the production vehicle is its steering wheel, with no joy-stick in sight.

Uniti One interior, available in gray. (Photo: Uniti)
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Hydrogen Station Explosion – Aftermath

The hydrogen station at Kjørbo is centrally located in Sandvika outside of Oslo, by two of the busiest roads in Norway with 80 000 cars passing daily. It is in Bærum municipality, and Akershus county. It exploded on Monday 2019-06-10. Since then, a number of interesting – some might say alarming – facts have emerged.

The station was a joint venture between X-Uno, Nel and Nippon Gases (formerly Praxair), announced on 2016-04-01. It uses Nel technology for on-site hydrogen production from electrolysis. The station is co-located with Powerhouse Kjørbo, an energy-positive office building, that uses solar panels that can supply upward of 200 000 kWh each year, twice the amount of the building’s annual energy consumption. Some of this excess energy was to be used to produce hydrogen.

The project had a total budget of NOK 28.4 million, of which NOK 5.7 million was support from the Akershus County Council and NOK 7.7 million was from the Norwegian public enterprise, Enova, responsible for the promotion of environmentally friendly production and consumption of energy. Other project partners included consulting firm Asplan Viak and Bærum Municipality.

Nel is an electrolysis technology company that has expanded into the hydrogen market. Its roots going back to technology developed by
Norsk Hydro in 1927. It is the world’s largest electrolyzer manufacturer with more than 3500 units delivered in over 80 countries. It is also a world leading manufacturer of hydrogen fuelling stations; approximately 50 stations delivered to 9 countries.

Safety Assessment

Bærum municipality has clearly stated that they did not have the competence to say whether the station was safe or not. They pointed out that the operator Uno-X sent its risk analysis to the Directorate for Civil Protection and Emergency Planning (DSB), relying on the authority to intervene if they saw the station as a security risk.

But DSB did not assess the analysis. Neither do they need to do so with anyone who stores or produces hydrogen in Norway. It emerges from DSB’s overview of hydrogen facilities in Norway, that the limit for having to get approval from the professional authority is actually set so high that it does not apply to anyone.

A total of 5 tonnes of hydrogen can be stored before it is subject to major accident regulations. Then another regulation on the storage of hazardous chemicals enters, which requires consent from DSB. That said, 100 grams of hydrogen can cause a serious situation if it is handled incorrectly, and less than one kilogram can lead to a fatal accident.

The 5 tonne limit is taken directly from Seveso, the relevant EU directive, which has been placed in the Norwegian major accident regulations. DSB is nevertheless free to demand that organizations obtain approval even if they are below the limit. However, DSB must argue that the risk dictates it, and then make a decision. It was not done at the hydrogen filling station in Sandvika. DSB is now also asking whether the limit of 5 tonnes of hydrogen is reasonable.

The amount of hydrogen stored when it exploded in the Uno-X station in Sandvika is uncertain, but in the safety analysis, the company estimates that they would store up to 100 kilograms during the first 1-2 years.

Leakage without Alarm

Perhaps the most disturbing fact emerging is that there was a hydrogen leak for an estimated 2.5 hours, that did not set off any alarms before the station exploded.

Nel installed the technology at the station and has admitted their responsibility for the explosion.

They are now reacting to the accident with a four point action plan. First, with a verified plug solution, they intend to inspect all high pressure storage units in Europe, and to check and re-torque all plugs. This should prevent the same circumstances arising in the future.

Second, they are updating their routines for assembly of high pressure storage units. This includes the introduction of a new safety system, and routines that follow an aerospace standard. This includes torque verification, double witness and documentation/marking.

Third, there is a need for improved leak detection, since it is estimated that hydrogen leaked from the tank for 2.5 hours, without this being detected. Thus, no alarm sounded before the tank exploded. Initially, this will involve a software update to increase leak detection frequency. However, they will also consider additional detection hardware and/ or modifications to the existing equipment.

Fourth, ignition control measures will have to be implemented. These are site dependent. A smooth surface, without gravel, should surround any high pressure storage unit. Additional ventilation may also be required, along with greater use of EX-equipment. That is, electrical equipment specifically designed for hazardous locations. This type of equipment should be specially designed and tested to ensure it does not initiate an explosion, including – but not restricted to – those due to arcing contacts or high surface temperature of equipment.

Incorrect Assembly of Equipment

The safety consulting company Gexcon, along with SINTEF and Bureau Veritas, is responsible for investigating the accident. They have found that a plug in one of the hydrogen tanks was mounted incorrectly and that this is why hydrogen leaked into the air and formed a cloud that eventually exploded.

On Friday, 2019-06-28, Nel, the company manufacturing the hydrogen distribution equipment, and who has taken responsibility for the explosion, explained how the incorrect assembly took place. Their presentation – which appears to be part public relations information about the company and part explanation for the incident – is here.

  1. Materials OK
    1. Magnetic particle inspection
    2. Penetrant testing
    3. Verification of materials
  2. Design OK
    1. 1 000 000 cycle accelerated test
  3. Assembly NOT OK
    1. Bolt analysis
    2. Physical gap
    3. Opening torque
  1. Starting condition.
    1. Green bolts torqued properly
    2. Blue bolts not torqued properly
  2. Red sealing fails.
    1. Starting with small leak on red sealing area
    2. Small leak wears red sealing out and escalates
    3. Large leak exceeding capacity of leak bore, causing pressure increases inside blue sealing area
  3. Bushing with Plug lifts and the blue seal fails.
    1. Insufficient pretension of bolts leads to lift of the plug and blue sealings fail immediately
    2. Spread of Hydrogen leaks out in uncontrolled way

There are two main candidates for ignition that are probably impossible to distinguish between. These are: 1. Self-ignition by static electricity mixed with optimum amount of oxygen and hydrogen led to ignition. 2. Gravel on the substrate at the tank, which lay at the very bottom in one corner. Wind acting on the gravel may have caused friction which led to ignition.

An additional report is expected to be released at the end of august 2019.

V2: The content was updated 2019-06-30 at 17:30.

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Hydrogen Station Explosion

2019-06-10, the Uno-X hydrogen station at Sandvika, near Oslo, Norway, was destroyed in an explosion. The explosion led to the activation of airbags in two nearby cars. (Photo: NRK)

An explosion, most likely in a single hydrogen tank, occurred at the Uno-X hydrogen station at Sandvika, near Oslo, on 2019-06-10. When writing this post, the cause of the explosion was not known.

While no one appears to have been directly injured in the explosion, two people driving in the vicinity were injured when their airbags activated because of air pressure from the explosion.

The explosion resulted in the closing, in both directions, of two major highways. European Highway 16 (E16) is the major east-west connection between Bergen and the Swedish border. The E18 connects southern Norway with Oslo.

For those interested in robotics, a LUF 60 wireless remote controlled mobile firefighting support machine, was actively used to suppress the fire that followed after the explosion. More importantly, it was used to cool other unexploded hydrogen tanks, to prevent them from exploding. In addition, a platform lift with water canon assisted with this task. These two vehicles allowed firefighters to keep their distance.

Norway’s other two hydrogen stations, one in Skedsmo, another Oslo suburb, and the other in Bergen, have now been closed.

According to Norwegian Hydrogen Forum as of 2018-12-31 there were 148 hydrogen cars registered in Norway: 57 Toyota Mirais, 27 Hyundai Nexos, and 64 Hyundai iX35s. In addition to this there are 5 buses and 1 truck. In contrast, as of the same date there were 200 192 plug in electric vehicles, plus 96 022 hybrid vehicles.

In another post titled Methane vs Electricity, a significantly flawed study from the Munich-based IFO Institute for Economic Research, was examined, along with its support for methane based, hydrogen vehicles.

With this explosion, hydrogen supporters in Norway will have lost much of the little good will that hydrogen fuel cells have built up. It has probably resulted in the last nail being put into the hydrogen car coffin.