Category Archives: Manufacturing

The Huge Scale of the Latest Generation of Wind Turbines is Challenging Available Manufacturing and Transportation Infrastructure

In an effort to improve the generating and economic performance of wind turbines, manufacturers have been designing and building increasingly larger machines.  Practical limits on transporting these very long and heavy components between the factories and the installation sites may limit the scale of the wind turbines selected for some applications and may require novel solutions that affect component design, factory siting and choice of transportation mode.  In this post, we’ll take a look at these issues.

1. The latest generation of wind turbines

1.1 GE Cypress platform

On 13 March 2019, General Electric (GE) Renewable Energy announced that its largest onshore wind turbine prototype, named Cypress, started commercial operation in the Netherlands.  Unlike other large wind turbines, the prototype Cypress composite turbine blades come in two pieces and are assembled on site. Cypress was announced in September 2017 and construction of the prototype began in 2018.

The 5.3 MW Cypress prototype wind turbine. Source:  GE

The Cypress 5.3-158 prototype has a nominal generating capacity of 5.3 MW.  A smaller Cypress 4.8-158 (with a 4.8 MW rating) is currently under production at GE’s Salzbergen, Germany factory, and it is expected to be commissioned by the end of the 2019.  Both have a rotor diameter of 158 meters (518.3 ft).

Anatomy of a GE Cypress wind turbine. Source:  GE

GE reports that the Cypress platform is “powered by a revolutionary two-piece blade design that makes it possible to use larger rotors and site the turbines in a wider variety of locations. The Annual Electricity Production (AEP) improvements from the longer rotors help to drive down Levelized Cost of Electricity (LCOE), and the proprietary blade design allows these larger turbines to be installed in locations that were previously inaccessible.” Site accessibility can be limited by the practicality of ground transportation of single-piece blades that can be nearly 91.4 meters (300 feet) long.

1.2 GE LM 88.4 P, the longest one-piece rotor blade in the world

LM Wind Power, a GE Renewable Energy business, has delivered the longest one-piece wind turbine blades built to date, the LM 88.4 P, which measure 88.4 meters (290 ft) long.  Three of these giant blades are installed onshore in Denmark on an Adwen’s AD 8-180 wind turbine, which has an 8 MW nominal generating capacity and a 180 meter (590.5 ft) rotor diameter.  You can get a sense of the size of an LM 88.4 P in the following photo showing a rotor blade leaving the factory.

88.4 meter (290 ft) LM 88.4 P wind turbine rotor blade 
leaving the factory.  Source: LM Wind Power

1.3 GE Haliade-X platform

GE is developing an even larger wind turbine platform, the Haliade X, which will become the world’s largest wind turbine when it is completed.  This 12 MW platform, which is being developed primarily for offshore wind farms, features 107 meter (351 ft) long one-piece blades and a 220 meter (722 ft) rotor diameter. The first prototype unit will be installed onshore near Rotterdam, Netherlands, where it will stand 259 meters (850 ft) tall, from the base of the tower to the top of the blade sweep.

Anatomy of a GE 12 MW Haliade-X wind turbine. Source: GE

Construction of the prototype Haliade-X wind turbine began in 2019.  The first blade is shown in the photo below. After securing a “type certificate” for the Haliade-X platform, GE plans to start selling this wind turbine commercially as early as 2021. The near-term market focus appears to be new wind turbines sited in the North Sea.

The first 107 meter (351 ft) Haliade-X blade at the factory in Cherbourg, France.  Source GE Renewable Energy

1.4 Siemens Gamesa SG 10.0-193 DD platform

In January 2019, Siemens Gamesa launched its next generation (Generation V) of very large offshore wind turbines, the SG 10.0-193 DD, which has a nominal generator rating of 10 MW, blade length of 94 meters (308 ft) and a rotor diameter of 193 meters (633 ft).  The nacelle housing the wind turbine hub and generator weighs up to 400 tons.

You’ll find the Siemens product brochure for this Generation V wind turbine here: https://www.siemensgamesa.com/en-int/-/media/siemensgamesa/downloads/en/products-and-services/offshore/brochures/siemens-gamesa-offshore-wind-turbine-sg-10-0-193-dd-en-double.pdf

The 10 MW Siemens SG 10.0-193 DD. Source: Siemens Gamesa

1.5 Vestas EnVestusTM platform

The EnVestusTM platform, which was introduced in 2019, is Vestas’ next generation in its evolution of wind turbines. The V162-5.6 MW has a rotor diameter of 162 meters (531 ft), which is the largest rotor size offered in the current EnVestusTM product portfolio.  Various tower sizes are offered, with hub heights up to 166 meters (545 ft).  With this tallest tower, the blade sweep of a V162-5.6 MW wind turbine reaches a height of 247 meters (810 ft).

V162-5.6 MW nacelle.  Source:  Vestas

The trend in Vestas wind turbine maximum rotor size is evident in the following diagram.  In comparison, the largest GE wind turbine, the Haliade-X will have a rotor diameter of 220 meter (722 ft), and the largest Siemens Generation V wind turbine will have a rotor diameter of 193 meters (633 ft).  

Source: Vestas

You can read and download the EnVestusTMproduct line brochure here: https://nozebra.ipapercms.dk/Vestas/Communication/Productbrochure/enventus/enventus-product-brochure/?page=1

2. Transporting very large wind turbine components

The manufacturer’s efforts to improve wind turbine generating and economic performance has resulted in increasingly larger machine components, which are challenging the limits of today’s transportation infrastructure as the components are moved from the manufacturer’s factories to the installation sites.  Here, we’ll look at the various ways these large components are transported.

2.1 Transportation of wind turbine components by land

Popular Mechanics reported that, “Moving long turbine blades is such a logistical nightmare that the companies involved sometimes resort to building new roads for the sole purpose of moving blades.” Transporting wind turbine tower and nacelle components can be equally challenging.  You’ll find an interesting assessment by CGS Labs of the challenges of wind farm ground transportation planning at the following link: https://www.cgs-labs.com/Software/Autopath/Articles/Windturbinetransport.aspx

As noted previously, the GE one-piece LM 88.4 P, which is 88.4 meters (290 ft) long, is the longest wind turbine rotor blade currently in service.  You can watch a short video of a single LM 88.4 P blade being transported 218 km (135 miles) to the construction site at the following link.  Total transport weight was 60 tons (120,000 lb, 54,431 kg). https://www.lmwindpower.com/en/products-and-services/blade-types/longest-blade-in-the-world

88.4 meter (290 ft) LM 88.4 P wind turbine blade during transport. 
Source: Screenshot from LM Wind Power video

Specialized trucks are employed to negotiate existing roads. Examples of difficult transportation situations are shown in the following photos.

Siemens 75 m (243 ft) rotor blade was transported 320 km (199 miles) by road.  Source: utilities-me.com, 14 Aug 2012
Making a sharp turn with a specialized truck for transporting a
 Vestas V117 57.5 meter (189 ft) wind turbine blade.  
Source: CNN.com, 5 October 2017

Watch a short 2017 video of this maneuver here:  https://www.youtube.com/watch?v=rxvuMv2MED0

Specially-designed trucks move 52.4 meter (172 foot) long wind turbine blades on narrow roads on Baoding Mountain in China.  Source:  Business Insider, 2 Mar 2017

Watch a short 2015 video of this amazing truck convoy here:  https://www.youtube.com/watch?v=1cnHui4pFBU

2.2. Transportation of wind turbine components by sea

The single-piece blades for the GE Haliade X wind turbine are so long that they couldn’t be transported by land from GE’s existing factories.  Therefore, a new LM Wind Power blade factory for the offshore wind market was built in Cherbourg, France, on the banks of the English Channel in Normandy.  This factory can load blades directly onto ships for delivery to offshore wind turbine sites.

GE wind turbine blades shipped by sea.  
Source:  LM Wind Power

In December 2016, Siemens Gamesa reported, “When our new factories in Hull, England and Cuxhaven, Germany become fully operational, and both Ro-Ro (“roll-on, roll-off”) vessels are in service as interconnection of our manufacturing and installation network, we expect savings of 15-20 percent in logistics costs compared to current transport procedures. This is another important contributor reducing the cost of electricity from offshore wind.”

The Hull, UK rotor blade factory, located at the Alexandra Docks on the harbor, was completed in 2016.  The Esbjerg, Denmark factory also is located on the harbor with direct access to shipping.

In 2018, Siemens Gamesa opened its modern factory in Cuxhaven, Germany for manufacturing offshore wind turbine nacelles.  These three Siemens wind turbine factories have direct Ro-Ro access to shipping.In November 2016, Siemens commissioned its first specialized Ro-Ro transport vessel, the Rotra Vente.  This ship is designed to transport multiple heavy nacelles, or up to nine tower sections, or three to four sets of rotor blades, depending on what else is being transported.  A second specialized Ro-Ro transport vessel, the Rotra Mare, was commissioned in the spring of 2017 to transport tower sections and up to 12 rotor blades.  These specialized transport vessels link the Siemens factories and transport the finished wind turbine components to the respective installation harbor.

The Rotra Vente provides Ro-Ro access for large Siemens wind turbine components.  Source: Siemens

2.3. Transportation of wind turbine components by airship

For more than two decades, there has been significant interest in the use of modern lighter-than-air craft and hybrid airships in a variety of heavy-lift roles.  One such role is the transportation of large wind turbine components.  Airships offer the potential to transport the components quickly between factory and installation site without the constraints of current ground and sea transportation networks.

Three examples of airship concepts for transporting wind turbine components are described below. 

Hybrid airships

In 2017, Lockheed-Martin proposed its LMH-1 hybrid airship to deliver large wind turbine components weighing up to 23.5 tons (47,000 lb; 21,000 kg).  The LMH-1 will be capable of flying 1,400 nautical miles (2,593 km) at a speed of about 70 knots (80 mph, 129 kph).  Lockheed-Martin is expected to fly the commercial prototype of its LMH-1 hybrid airship in 2019. You can read Lockheed-Martin’s proposal for airship transport of wind turbine components here: https://www.lockheedmartin.com/content/dam/lockheed-martin/eo/documents/webt/transporting-wind-turbine-blades.pdf

This type of airship conducts short takeoff and landing (STOL) operations when transporting heavy loads, but can operate from relatively unprepared sites.  When off-loading heavy cargo, this airship must take on ballast at the landing site. 

After LMH-1, Lockheed Martin has plans to build a medium-size (90 ton cargo) hybrid airship that would be more competitive with trucking and rail transport.  

Anatomy of the LMH-1 hybrid airship.  Source:  Lockheed Martin

Variable buoyancy airships

In January 2013, Worldwide Aeros Corp. (Aeros), located in Montebello, CA, conducted the first “float test” of their Dragon Dream variable buoyancy airship.  More recently, Aeros has reported that they are working on the first commercial prototype of a larger variable buoyancy airship to be known as the ML866 / Aeroscraft Gen 2, which will be 169 meters (555 ft) long.  This airship is being designed with great range (3,100 nautical miles; 5,741 km) and a cruise speed of 100 – 120 knots.  The ML866 will have a cargo capacity of 66 tons (132,000 lb; 59,874 kg).  The first ML866 prototype is not expected to fly before the early 2020s.

This type of airship is designed to conduct vertical takeoff and landing (VTOL) operations with a full cargo load, and can hover above a site and take on or deliver cargo without landing and without transferring ballast to/from the ground site.

Concept drawing of an Aeroscraft variable buoyancy airship delivering wind turbine blades to a site.  Source: Worldwide Aeros Corp.

Semi-rigid airships

The KNARR initiative is a project created by two Danish design architects, Rune Kirt and Mads Thomsen to design a freight solution using modern airships to reduce the cost and energy consumption of today’s wind turbine freight business and make the logistics for wind turbine freight simpler and more efficient.  Their main point is that transportation and installation costs can be up to 60% of the total cost of a new wind turbine, and these activities have a large carbon footprint.  Their solution is a modern airship that is designed specifically for transporting very large and heavy wind turbine components directly from the manufacturer’s factory to the installation  site. For their work, they were awarded both the Danish Design Center’s Special Prize and the International Core77 Design “Speculative Concept.”.  You can read more about the firm, KIRT x THOMSEN aps, and the KNARR initiative here: https://www.kirt-thomsen.com/case10_airship-knarr

and here: https://projectknarr.wordpress.com/what-is-knarr/

The KNARR semi-rigid airship would be 360 meters (1,181 ft) long and would carry the wind turbine components in a large internal cargo bay. This type of airship is designed to conduct VTOL operations with a full cargo load.  When off-loading heavy cargo, this airship must take on ballast at the landing site.

The KNARR airship is a concept only.  No prototype is being built at this time.  You can view a short video defining the wind turbine transport application of KNARR airship here: https://vimeo.com/21023051

Concept drawing of a KNARR airships it lifts off after making a delivery.
Source: https://www.kirt-thomsen.com/
Concept drawing of a KNARR airship flying over a wind farm.
Source: https://www.kirt-thomsen.com/

3. Conclusions

The scale of the latest generation of wind turbines, particularly the GE LM 88.4 P, which measure 88.4 meters (290 ft) long, is approaching the limits of existing ground transportation infrastructure to handle delivery of such blades from the factory to the installation site.  GE’s introduction of two-piece blades on their new Cypress platform will significantly improve the logistics for delivering these large blades to installation sites.

Siemens’ practice of siting its wind turbine component factories with ready access to Ro-Ro shipping at an adjacent port facility greatly reduces the complexity of delivering large components to a port near an installation site.  GE has adopted the same approach with their latest factory for manufacturing the Haliad-X rotor blades in Cherbourg, France, on the English Channel.

Airships could revolutionize the transportation of large, heavy items such as wind turbine components.  However, the earliest likely candidate, the Lockheed Martin LMH-1 will not be available until the early 2020s and will  be limited to a maximum load of 23.5 tons (47,000 lb; 21,000 kg).  It seems unlikely that larger heavy-lift airships will be introduced before about 2025. 

So, in the meantime, we’ll see the largest wind turbines being installed in offshore sites.  For onshore sites, we’ll see more creative ground transportation schemes, and, probably, a broader introduction of multi-part rotor blades.

4. Recommended additional reading on wind turbines:

Post-World War II Prefabricated Aluminum and Steel Houses and Their Relevance Today

With the decline of military aircraft production after World War II (WWII), the U.S. aircraft industry sought other opportunities for employing their aluminum, steel and plastics fabrication experience in the post-war economy. In the 2 September 1946 issue of Aviation News magazine, there was an article entitled “Aircraft Industry Will Make Aluminum Houses for Veterans,” that reported the following:

“Two and a half dozen aircraft manufacturers are expected soon to participate in the government’s prefabricated housing program.”

“Aircraft companies will concentrate on FHA approved designs in aluminum and its combination with plywood and insulation, while other companies will build prefabs in steel and other materials. Designs will be furnished to the manufacturers.”

“Nearly all war-surplus aluminum sheet has been used up for roofing and siding in urgent building projects; practically none remains for the prefab program. Civilian Production Administration has received from FHA specification for aluminum sheet and other materials to be manufactured. ….Most aluminum sheet for prefabs will be 12 to 20 gauge – .019 – .051 inch.”

Under the government program, the prefab home manufacturers were protected financially with FHA guarantees to cover 90% of costs, including a promise by Reconstruction Finance Corporation (RFC) to purchase any homes not sold. In addition, these manufacturers were to be given preferred access to surplus wartime factories that could be converted for mass-production of homes.

The business case for the post-war aluminum and steel pre-fabricated homes was that they could be sold profitably at a price that was substantially less than conventional wood-constructed homes.

Not surprisingly, building contractors were against this program to mass-produce pre-fabricated homes in factories. Moreover, local building codes and zoning ordnances were not necessarily compatible with the planned large scale deployment of mass-produced, prefabricated homes.

Now consider the most common housing problem of today, which seems to me to be a shortage of available low-cost housing. In recent years, this has sparked the “tiny home movement,” which is a social and architectural movement promoting living simply in small homes. Seventy years after the end of WW II, it may be time to reconsider the use of mass-produced, prefabricated aluminum and steel homes to address the current shortage of low-cost housing.

Let’s take a look at several of these efficient, and sometimes stylish post-war prefabricated homes:

  • Beech Aircraft’s aluminum Dymaxion house
  • Consolidated Vultee’s aluminum Fleet house
  • Lustron’s steel houses
  • Lincoln Houses Corporation’s aluminum houses
  • Alcoa’s mid-century modern aluminum Care-free houses
  • UK’s AIROH aluminum houses
  • UK’s Arcon steel-framed houses
  • French architect Jean Prouvé’s “Demountable house”

Beech Aircraft Corporation planned to mass-produce R. Buckminster Fuller’s Dymaxion house

In 1927, R. Buckminster Fuller developed plans for the Dymaxion (acronym for “dynamic, maximum, tension”) house, which was intended to be a mass-produced metal house of novel circular design.

Early interest in applying aircraft aluminum manufacturing techniques to post WWII housing construction was expressed by Beech Aircraft Corp. In 1944, Beech established a joint project with Dymaxion Dwelling Machines, Inc. (later renamed Fuller Houses, Inc.) to manufacture a prototype, updated Dymaxion house in Wichita, Kansas. The strong aluminum riveted structure and skin was built from WWII surplus material, with the aluminum-domed roof hung from a stainless steel strut; providing 1,017 ft2 of floor space. The aluminum, stainless steel and plastic house weighted about 8,000 pounds and was designed to withstand severe weather, including tornados.

Dymaxion HouseSource: Aviation News magazineDymaxion Wichita houseSource: TournaTalk, tournatalk.wordpress.comDymaxion floorplanDymaxion house floor plan. Source: Pinterest

The 1 April 1946 issue of Aviation News magazine reported:

“Beech Aircraft Corp. expected to build 200 of these houses a day soon after the start of 1947, according to Herman Wolf, president of Fuller Homes, Inc., which will market the dwelling designed by R. Buckminster Fuller……..The houses will be subcontracted to construction firms which will combine aircraft technology and auto mass production methods. Wolf and Fuller see the new dwellings, which will sell for $6,500 erected, as the answer to the veterans housing problem. City building codes are the big imponderable in forecasting the success of this dwelling.”

Only two Dymaxion houses were built. One is now in the Henry Ford Museum in Dearborn, Michigan.

You can read more about the Dymaxion house at the following links:

http://www.bfi.org/about-fuller/big-ideas/dymaxion-world/dymaxion-house

and

http://b2dymaxionhouse.blogspot.com/p/mass-production.html

Consolidated Vultee Aircraft Corporation built the Fleet House

The California aircraft manufacturer Consolidated Vultee (later Convair) considered mass-producing a pre-fabricated homes for the post-WWII housing market. Collaboration with industrial designer Henry Dreyfuss and architect Edward Larrabee in 1947 led to the design of a small two-bedroom home. With kitchen appliances, kitchen and bathroom fixtures, and heating, the house was expected to sell for $7,000 – $8,000, including the cost of the lot.

Fleet house in factoryThe Fleet House in the factory. Source: www.thefleethouse.comFleet house exterior viewThe Fleet House exterior view. Source: www.thefleethouse.com

Only two prototypes were manufactured in 1947.

An article by Jeffrey Head entitled “Snatched from Oblivion,” on the Metropolis website reported:

“Comprising 28 parts, the two-bedroom, one-bath structure appears larger than its 810 square feet because 75 percent of the exterior walls are windows. The remaining interior, roof, and garage walls are constructed of “lumicomb,” a lightweight material made of a cardboard-like honeycomb core bonded between sheets of high-strength aluminum, used at the time for airplane bulkheads. The lumicomb adds to the open feeling of the house by requiring less floor space than traditional wall and roof construction.”

“Because the resulting design was so unorthodox, Reginald Fleet, president of Southern California Homes Incorporated, opted for a novel way of marketing it. Fleet resided in the prototype with his wife and daughter, leaving it open for prospective buyers to see what life was like in a modern prefabricated home.”

“New owner Sergio Santino was about to close escrow and planned to raze the house until the South Pasadena Cultural Heritage Commission informed him of its significance.”

You can read Jeffrey Head’s complete article at the following link:

http://www.metropolismag.com/October-2006/Snatched-from-Oblivion/

Much more information is available at the Fleet House website at the following link:

http://www.thefleethouse.com

Here it is noted:

“Historically known as the “Consolidated Vultee House”, and commonly referred to as “the Fleet House”, today it may be the only structure still remaining that was designed, built and pre-assembled entirely in an aircraft factory.”

“The Fleet House is featured in Taschen’s PREFAB HOUSES 2010.  It is referenced in numerous publications documenting the history of pre-fab housing and has been photographed by noted post WWII architectural photographer Julius Shulman.”

Fleet House today The Fleet House today. Source: www.thefleethouse.com

Lustron Corporation offered low-maintenance steel homes

The Lustron Corporation, formed in 1947 by Carl Strandlund, received financing from RFC to mass-produce steel pre-fabricated houses in a former Curtiss-Wright aircraft factory in Columbus, OH.

Lustron homes came in 2- and 3-bedroom models ranging in size from 713 ft2 to 1,140 ft2. All homes came standard with enamel-coated steel exterior panels, enamel-coated steel shingle roof, metal ceiling tiles and metal-paneled interior walls, metal cabinets, closets with pocket doors, and service and storage areas.

Below is a 1949 photo of the prefabricated components of a Lustron house.

Lustron components laid outSource: Pinterest

Lustron Esquire floor plan

Floor plan of a 2-bedroom Lustron “Esquire” model. Source: http://instanthouse.blogspot.com

Lustron finished house         A finished Lustron house. Source: Pinterest

Original plans were to manufacture more than 10,000 homes per year. Actual production was much less, with a total of 2,498 Lustron homes manufactured between 1948 and 1950. House prices were in the $8,500 – $9,500 range, increasing to an average of about $10,500 by the end of 1949. This was approaching the price of a comparable, conventional, wood-constructed house.

The Lustron Corporation declared bankruptcy in 1950. The business failed because of several factors, including production delays, poor distribution strategy, and escalating prices that reduced the price advantage of a pre-fabricated house.

About 2,000 Lustron homes still exist today. You can read more on Lustron houses at the following link:

http://instanthouse.blogspot.com/2011/08/lustron-house.html

Lincoln Houses Corp. offered 2- and 3-bedroom aluminum homes

During WWII, Lincoln Industries developed processes for making structural material at low cost for radar housings. This process led to the design of 4’ x 8’ structural panels for buildings that were manufactured using the following process:

“Lincoln plastic panels are made by alternating sheets of heavy paper, cloth, or glass cloth with glue strips. When the desired thickness is obtained, the sheets are expanded on an automatic machine to form a honeycomb pattern. This honeycomb core is thoroughly impregnated with high-strength phenolic resin and then bonded between facing sheets of aluminum alloy, and the entire panel sealed with a vapor barrier.”

This material provides both great strength and high insulating properties. The bearing capacity of a two-inch thick wall panel compared favorably with the load carrying capacity of a brick wall one foot thick. The three-inch thick roof panels were designed to withstand an eight-foot snow load.

The basic house contained two bedrooms, a bath, living room, kitchen, dining room and general utility room. Under the Veteran’s Emergency Housing Program, the Lincoln pilot plant in Marion, Virginia manufactured and sold 2-bedroom homes for about $3,500 – $4,000 and a 3-bedroom home for about $4,500, including, “wiring, water piping and heating,” constructed on a concrete or similar slab. These prices did not include the price of the land or the price of kitchen appliances and a hot water heater. Construction took about two days.

Lincoln pre-fab aluminum homeSource: Aviation News magazine

The house was designed for severe weather and the materials of construction provided protection against dry rot, internal condensation and termites.

By 1946, numerous Lincoln aluminum homes had been built and were in use. However, it appears that Lincoln never made the transition to large scale production in former airplane factories.

Aluminum Company of America (Alcoa) offered mid-century modern aluminum Care-Free Homes

After WWII, aluminum manufacturers were faced with large stocks of aluminum ore and decreasing orders. Like the aircraft manufacturers, Alcoa sough alternate markets for their finished aluminum products.

A decade after the end of WWII, Alcoa offered the Care-Free Home, which was a mid-century modern aluminum ranch house designed by Charles M. Goodman. Originally, Alcoa planned to build one Care-Free home in each of the 48 states to showcase the versatility of aluminum in home construction. A total of 24 Care-Free homes were built. The house has a 1,900 ft2 living area, a full basement, and a 2-car carport.

The framing is aluminum and wooden columns are clad in aluminum. The exterior is aluminum siding with big, aluminum-framed windows and sliding doors, and an aluminum front door. The roof and fascia strip also are aluminum. The originally expected price was about $25,000, but actual cost was almost double. In the mid-1950s, the Care-Free house couldn’t compete with the lower cost of conventional wood construction.

Alcoa Care FreeSource: Alcoa 1957 brochure

Alcoa Care Free floor planSource: Alcoa 1957 brochure

You can download a 1957 Alcoa sales brochure on the aluminum Care-Free Home at the following link:

http://media.oregonlive.com/hg_impact/other/Care%20Free%20Home%20compressed%20version.pdf

Post-war prefabricated aluminum and steel homes in the UK

In 1944, the UK Ministry of Works held a public display at the Tate Gallery in London of five types of prefabricated homes.

  • One aluminum prefab, made from surplus aircraft materials, the AIROH (Aircraft Industries Research Organization on Housing)
  • One steel-framed prefab with asbestos panels, the Arcon, which was adapted from the all-steel Portal prototype
  • Two timber-framed prefab designs, the Tarran and the Uni-Seco

This popular display was held again in 1945.

In comparison to the very small number of post-war aluminum and steel prefabricated homes built in the U.S., the production in the UK was very successful.

The AIROH aluminum house

An pre-fab package for an AIROH house consisted of 2,000 components that were assembled in four sections and delivered to the intended site by truck. The fully equipped bungalow weighed about 10 tons and provided 675 ft2 of living space, including a fully equipped kitchen and bath. In 1947 an AIROH home cost £1,610 ($6,488 @ $4.03 USD/£ in 1947) each to produce, plus cost of the land and installation. A total of 54,500 AIROH homes were constructed.

AIROH home module on truck           Source: Architects’ Journal, vol. 101, 1945 Apr. 19, p. 452

airoh_poster           Source: https://peterdewrance.files.wordpress.com

airoh_prefab_floorplanSource: https://peterdewrance.files.wordpress.com

More information on the AIROH aluminum prefabricated house can be found at the following link:

https://peterdewrance.wordpress.com/2015/08/14/prefab-days/comment-page-1/

The Arcon steel-framed house

The steel-framed Arcon prefabricated home had two bedrooms, fully equipped kitchen and bath and included steel built-in cabinets in the kitchen, bath and bedrooms. Exterior walls and roofing were made of corrugated asbestos panels. The house was manufactured in four 7ft-6in wide sections to enable road transportation to a pre-prepared site where the house was assembled. An Arcon house cost £1,209 ($4,872 U.S. @ $4.03 USD/£ in 1947) each to produce, plus cost of the land and installation. A total of 38,859 Arcon homes were constructed.

Arcon Mk VArcon Mk V at Avondale Museum of Historic Buildings, UK. Source: avoncroft.org.uk

Arcon Mk V floorplanArcon Mk V bungalow floor plan. Source: iwmes.org.uk/prefab.html

More information on the Arcon steel-framed prefab house is available at the following link:

http://www.iwmes.org.uk/prefab.html

More information on the broader UK efforts to address their post-war housing shortage with mass-produced prefabricated homes of all types is available at the following link:

https://en.wikipedia.org/wiki/Prefabs_in_the_United_Kingdom

Post-war prefabricated metal frame homes in France

A notable French design was Jean Prouvé’s “Demountable House,” which was developed in 1946 under a commission from the Ministry of Reconstruction and Town Planning for use as temporary bungalows for post-war housing for Lorraine, France. The metal frame load-bearing structure of the Demountable House is shown in the first photo below. Panels of various types are then attached to the frame to complete the exterior of the house and any internal room partitions.

Jean Prouve frame

Jean Prouve partial skinFrame for an 8 x 8 Demountable house. Source: http://www.dwell.com/rewind/article/progressive-prefabs-jean-prouvé

To demonstrate the ease with which Prouvé’s pre-fabricated house can be assembled on site, one model was built and then taken apart every day during Art Basel Miami 2013.

You’ll find more information on Prouvé’s pre-fabricated houses and other buildings at the following links:

http://socks-studio.com/2013/12/17/jean-prouves-experimental-prefabricated-houses/

and

http://www.patrickseguin.com/en/designers/architect-jean-prouve/available-houses-jean-prouve/

In conclusion

In the U.S., the post-war mass production of prefabricated aluminum and steel houses never materialized. Lustron was the largest manufacturer with 2,498 houses. In the UK, over 93,000 prefabricated aluminum and steel houses were built as part of the post-war building boom that delivered a total of 156,623 prefabricated houses of all types between 1945 and 1951, when the program ended.

The lack of success in the U.S. arose from several factors, including:

  • High up-front cost to establish a mass-production line for prefabricated housing, even in a big, surplus wartime factory that was available to the manufacturer on good financial terms.
  • Immature supply chain to support factory operations.
  • Ineffective distribution and delivery infrastructure.
  • Unprepared local building codes and zoning ordnances.
  • Opposition from construction workers and unions that did not want to lose work to factory-produced homes.
  • Manufacturing cost increases, which reduced or eliminated the price advantage of the prefabricated homes.

From these post-war lessons learned, and with the renewed interest in “tiny homes”, it seems that there should be a business case for a modern, scalable, smart factory for the low-cost mass-production of durable prefabricated houses manufactured from aluminum, steel, and/or other materials. These prefabricated houses should be modestly-sized, modern, attractive, and customizable to a degree while respecting a basic standard design. These houses should be designed for siting on small lots in urban or suburban areas and for rapid construction.

The UK post-WWII prefab housing boom lasted seven years and delivered low-cost housing for about a half million people. I believe that there is a large market in the U.S. for this type of low-price housing, but great obstacles must be overcome, especially in California, where nobody will want a modest prefabricated home sited next to their McMansion.

 

 

 

 

Polymagnets® will Revolutionize the Ways in Which Magnets are Used

The U.S firm Correlated Magnetics Research (CMR), Huntsville, AL, invented and is the sole manufacturer of Polymagnets®, which are precision-tailored magnets that enhance existing and new products with specific behaviors that go far beyond the simple attract-and-repel behavior of common magnets. Polymagnets have been granted over 100 patents, all held by CMR. You can visit their website at the following link:

http://www.polymagnet.com

CMR describes Polymagnets® as follows:

“Essentially programmable magnets, Polymagnets are the first fundamental advance in magnets in 180 years, since the introduction of electromagnets. With Polymagnets, new products can have softer ‘feel’ or snappier or crisper closing or opening behavior, and may be given the sensation of a spring or latch”.

On a conventional magnet, there is a North (N) pole on one surface and a South (S) pole on the opposite surface. Magnetic field lines flow around the magnetic from pole to pole. On a Polymagnet®, many small, polarized (N or S) magnetic pixels (“maxels”) are manufactured by printing in a desired pattern on the same surface. The magnetic field lines are completed between the maxels on that surface, resulting in a very compact, strong magnetic field. This basic concept is shown in the following figure.

Polymagnet field comparison

The mechanical 3-D behavior of a Polymagnet® is determined by the pattern and strength of the maxels embedded on the surface of the magnet. These customizable behaviors include spring, latch, shear, align, snap, torque, hold, twist, soften and release. The very compact magnetic field reduces magnetic interference with other equipment, opening new applications for Polymagnets® where a conventional magnet wouldn’t be suitable.

The above figure is a screenshot from the Smarter Every Day 153 video, which you can view at the following link. Thanks to Mike Spaeth for sending me this is a 10-minute video, which I think you will enjoy.

https://www.youtube.com/watch?v=IANBoybVApQ

More information on Polymagnet® technology, including short videos that demonstrate different mechanical behaviors, and a series of downloadable white papers, is available at the following link.

http://www.polymagnet.com/polymagnets/

This is remarkable new technology in search of novel applications. Many practical applications are identified on the Polymagnet® website. What are your ideas?

If you really want to look into this technology, you can buy a Polymagnet® demonstration kit at the following links:

https://www.magnetics.com/product.asp?ProductID=164

or,

http://www.mechanismsmarket.com/kits/

Polymagnet demo kit   Source: Mechanisms Market

 

First Ever 3D Printed Object Made From Asteroid / Meteorite Metals

In a 31 December 2015 post, I discussed the “U.S. Commercial Space Launch Competitiveness Act,” which was signed into law on 25 November 2015 and established, among other things, the legal basis for asteroid mining. I also identified the firm Planetary Resources (http://www.planetaryresources.com/ – home-intro) as one of the firms having a business interest in asteroid prospecting.

Today, at the Consumer Electronics Show (CES) today in Las Vegas, Planetary Resources announced that they, in collaboration with their partner firm, 3D Systems (http://www.3dsystems.com), have produced the first ever direct metal print of an object using metals recovered from an asteroid (or meteorite) that impacted Earth.

PlanetaryResources_3DSystems_Meteorite2_LOW-680x355 Source: Planetary Resources

In the Planetary Resources announcement, they stated that the material used for 3D printing:

  • “…was sourced from the Campo Del Cielo impact near Argentina, and is composed of iron, nickel and cobalt – similar materials to refinery grade steel.”
  • “ …was pulverized, powdered and (then) processed on the new 3D Systems ProX DMP 320 metals 3D printer.”

You can read the announcement at the following link:

http://www.planetaryresources.com/2016/01/planetary-resources-and-3d-systems-reveal-first-ever-3d-printed-object-from-asteroid-metals/

You can read more about the ProX DMP 320 3D printer at the following link:

http://www.3dsystems.com/3d-printers/production/prox-dmp-320

The milestone announced today demonstrates a key capability needed for building research bases and commercial facilities in space using raw materials found on another body in our solar system.

Imagine what the cargo manifest will be on future space missions to destinations that have useful natural resources that can be mined and prepared on site for use in various 3D printing (additive manufacturing) activities. The early missions will need to carry pre-fabricated structures for an initial base, tools for initial mining and manufacturing work, other items manufactured on Earth, and consumables. Once the on-site mining and manufacturing facilities reach an initial operating capability, the extended supply chain from Earth can be reduced commensurate with the capabilities of the local supply chain.

For more background information on this subject, National Academies Press published the  report, “3D Printing in Space”, which you can download for free at the following link if you have set up a MyNAP account:

http://www.nap.edu/catalog/18871/3d-printing-in-space

18871-0309310083-450  Source:  NAP

Opportunities for 3D printing in space addressed in this NAP report include: manufacturing new or replacement parts needed on a space vehicle or off-Earth facility; creating structures that are difficult to produce on, or transport from, Earth; creating a fully-printed spacecraft; using resources available on planetary surfaces; recycling materials in space; and establishing a free-flying fabrication facility.  The report also includes roadmaps for NASA and the U.S. Air Force deployment of 3D printing capabilities in space.

This is just the start. Manufacturing in space using locally sourced materials will revolutionize our approach for building a permanent human presence off the planet Earth.

 

Scalability of 3-D Printing (additive manufacturing)

We are only now starting to see the very broad implications of 3-D printing technology in many disciplines, some of which would not be considered as traditional “manufacturing” activities. Since the “ink” can be almost anything, and the scalability of the technology is vast, the potential applications are much broader than the early applications conceived so far.

Here are a couple of examples that illustrate the scalability of 3-D printing technology and show how the computer system driving the printer adds a layer of intelligence needed to manufacture remarkable products.

Where do you see applications for this technology?

Medical application: Treating burn victims

In Feb 2015, Wake Forest School of Medicine announced that it had designed, built and tested a printer capable of printing skin cells directly onto burn wounds. The “ink” is actually different kinds of skin cells. A scanner is used to determine wound size and depth. Different kinds of skin cells are found at different depths. With this data, a computer guides the printer as it applies layers of the correct type of cells to cover the wound.   Read the story at the following link:

http://www.wakehealth.edu/Research/WFIRM/Research/Military-Applications/Printing-Skin-Cells-On-Burn-Wounds.htm

Another approach for treating burn victims was announced in 2014 by the University of Toronto. Their solution is called the “PrintAlive” 3-D bioprinter, which is  capable of manufacturing continuous layers of tissue – including hair follicles, sweat glands and other human skin complexities – onto a hydrogel that can be used in place of conventional skin grafts. Read the story at the following link:

http://www.gizmag.com/printalive-biopronter-skin-grafts-burns/34057/

The students who developed the PrintAlive machine were the Canadian winners of the 2014 James Dyson Award, that is intended to that celebrate, encourage and inspire the next generation of design engineers.

Construction application: Building a house

This is a really large-scale application of 3-D printing technology that also requires a stock of certain parts that are more easily emplaced where needed rather than printing them in place (i.e., windows, doors, floors and ceilings). Additive manufacturing could be used to separately produce most of these emplaced items.

Contour-Crafting-USC-635-3D-Printer

Read the article and see the 6 min video of the construction process at the following link:

http://gadgets.ndtv.com/laptops/news/new-giant-3d-printer-can-build-a-house-in-24-hours-470564?utm_source=howtogeek&utm_medium=email&utm_campaign=newsletter