Burckhardt Compression has been supplying Laby® compressors for gas ships for over half a century from its Winterthur works in Switzerland. This proud company, which still bears the founder’s name, was established in 1844 as ‘Franz Burckhardt, mechanic’ in Basel.
Worldwide recognition and commercial success for any product or equipment invariably comes from a basic design idea that is sound and simple. Burckhardt’s Laby piston compressor meets these criteria thanks to its unique labyrinth sealing system on the piston and piston rod gland which allows oil-free and contact-free compression. In addition the crankcase is gas-tight and able to resist the pressure required for each application. The simple design also ensures that maintenance requirements are minimal.
Introduced in 1935, the Laby compressor was originally designed for the safe compression of ammonia in land-based applications. Burckhardt developed its first designs for shipboard use in the early 1960s, and in 1964 the 1,400m3 LPG carrier Gaston Micard, built by the Jos L Meyer yard, became the first gas ship fitted with Laby compressors. Three K80-1A units were installed onboard.
Following this initial order Burckhardt delivered shipboard compressors for some notably historic gas ship newbuildings. These included Norway’s first fully refrigerated LPGC, the 11,000m3 Havgas from Moss Værft in 1965, and the pioneering 824m3 ethylene carrier Lincoln Ellsworth, completed by AG Weser in 1966. The company’s compressors were also installed on the first Sweden-built gas carrier, the 25,000m3 fully refrigerated LPGC Paul Endacott, completed by Kockums in 1964.
In 1969 the Burckhardt engineering works was taken over by the Sulzer Group and began operating as Sulzer Burckhardt. For many seafarers and cargo engineers at that time, the ‘Sulzer’ brand name was used when referring to the onboard compressors in the reliquefaction house. Following a management buyout in 2002 the company became legally independent and began trading under its present name.
The 1970s represented a notable decade for Sulzer Burckhardt. A standout contract was the supply of three Laby compressors for the largest LPG carrier ever built, the 101,000m3 Esso Westernport, built by Chantiers Navals de la Ciotat in France.
Later that decade, at another French yard, the company had its first encounter with LNG carriers. Sulzer Burckhardt compressors were specified as part of the combined LPG/LNG reliquefaction system required for each of a pair of 126,000m3 ships built by l’Atlantique for Compagnie Nationale Algérienne de Navigation (CNAN). The first of the two LNG/LPG carriers, Mourad Didouche, was delivered in July 1980 while Ramdane Abane followed 12 months later.
The gas plant was designed as a partial LNG reliquefaction system, as the designers predicted that only one-third of the cargo heel would be needed as fuel for the ballast leg. The systems were the first to be built for shipboard LNG reliquefaction. Both ships are still in service and have traded exclusively with LNG cargoes, so there is every probability that the combined LPG/LNG reliquefaction capability has never been used.
Burckhardt works in close co-operation with major European and Asian designers of gas-handling systems for ships. As a result Burckhardt has taken a leading position in supplying compressors for semi-pressurised/fully refrigerated (semi-ref) ethylene carriers and LPGCs, fully refrigerated LPGCs and small-scale LNGCs.
The construction material of the Laby compressor crankcases is required to match the liquid temperature of the gases handled. Standard gray cast iron is used for LPG and anhydrous ammonia and a 35 per cent nickel cast iron for the first stage of compression for LNG.
The Swiss company also has an extensive reference list of labyrinth-piston compressors that have been provided for LNG terminals. Its equipment can be found at a range of export and import facilities in the Middle East, South East Asia, North Asia, Europe and the Americas.
Over the past decade the LNG industry has introduced an unprecedented series of technical innovations. These have taken the form of ships of smaller and larger sizes, new propulsion systems, floating LNG production and regasification vessels and LNG-powered ships. Burckhardt Compression has utilised its experience of LPG and petrochemical gas carriers and of LNG terminals to adapt its equipment for the evolving requirements of the LNG supply chain.
The first result of the company’s LNG development programme is the Laby®-GI fully balanced boil-off gas compressor for use with dual-fuel propulsion systems on LNG carriers and in FLNG offshore applications. John Linwood, Burckhardt’s segment manager for gas transport and storage, modestly states, “The use of small LNG ships for onward distribution from large LNG receiving terminals is presenting an exciting new market opportunity and we have supplied a good number of compressor units for such vessels.”
The first small-scale LNGC with Burckhardt compressors to enter service was the 1,100m3 Pioneer Knutsen, delivered by Dutch shipbuilder Bijlsma for Knutsen OAS in March 2004. The second was the 7,500m3 Coral Methane, a vessel completed for Anthony Veder in April 2009 by Remontowa in Poland.
Other small-scale LNGCs with Laby compressors now in service include the six Multigas ships of 10,000-12,000m3 built in China for IM Skaugen and Veder’s 15,600m3 Coral Energy. The company’s equipment has also been specified for several larger coastal distribution LNGCs of 28-30,000m3 currently on order in China.
Burckhardt made its breakthrough into the floating LNG vessel sector when it secured a contract to supply a skid-mounted Laby-GI compressor as part of the Golar Freeze conversion project. The 126,000m3 Moss spherical tank ship was transformed into a floating storage and regasification unit (FSRU) by Keppel Shipyard for service in Dubai. The vessel commenced operations in its new role in 2011.
Another new LNGC application for the Laby-GI compressor is in tandem with the low-speed, gas-injection ME-GI engines developed by MAN Diesel and Turbo. A global oil and gas shipping company has ordered four 170,000m3 ships at a Korean shipyard with this dual-fuel propulsion system, the first LNG carriers to be so powered, and Burckhardt has been contracted to supply its units for the vessels. The two-stroke ME-GI engines that will propel the ships require the introduction of fuel gas at high pressure, and the Laby-GI units for this application will be able to deliver gas at more than 30,000 kPa.
While the fundamentals of its compressor design have not changed much over time, scale has, and compressor size provides a good illustration of the progress made by Burckhardt Compression in the gas ship sector over the past 50 years. Back in 1974 each of the K80-1A units on the 1,400m3 Gaston Micard was 615mm long, 550mm wide and 1,342mm high. For the Laby-GI 4LP250-3A units on the 126,000m3 Golar Freeze FSRU the equivalent dimensions are 5,600 x 2,200 x 4,800mm. LNG
This article was written by Syd Harris