• TBM Bertha breaks through in Seattle

  • Mighty Hitachi TBM tested before delivery to Seattle

  • Waterview highway tunnel progress and breakthrough
DISCUSSION FORUM Tracking the world's mega-TBMs 07 Mar 2019
TunnelTalk reporting
With delivery of the first of two 15.6m Herrenknecht EPBMs to Melbourne, Australia, for the West Gate twin-tube, three traffic lanes in each, highway tunnel project has the world’s newest mega TBMs manufactured and being readied for assembly and launch.
15.6m cutterhead preparing for TBM assembly

15.6m cutterhead preparing for TBM assembly

The two mega TBMs for Melbourne brings the total number of mega TBM tunnel projects in the world to 39, since the first in Japan in 1994. Some have engaged two or more mega machines operating on the same project, and some projects have been completed by a rebuild of mega machines used on previous projects. Keeping tack of the mega TBMs and their projects in the world, TunnelTalk has published technical articles on several of those world-leading projects to provide a valuable record of the design, manufacture and experiences of these giants of more than 14m diameter (Table 1).
The two mega machines in Melbourne are procured by the CPB/John Holland JV which is engaged by the concessionaire Transurban under its PPP (private-public-partnership) agreement with the State Government of Victoria.
The massive 15.6m diameter cutterheads of the two Herrenknecht EPBMs are dressed with 96 x 19in cutters - six sets of twin cutters and 84 single cutters - and a triple ring, hydraulically operated over-cutter. In addition there are 152 scraper tools and 16 outer scrapers on each cutterhead. The machines have about 12MW of total installed electrical components and a new substation has been built on the northern portal launch site of the project to supply about 10 MW of electricity from twin mains feed supplies, to power each on a 24 hrs/day, 7 days/week schedule. With a variable speed of 0 to 1.9 rev/min in normal operation, and up to 3.5 rev/min for the outbound machine through a section of rock, maximum nominal torque on the cutterheads is 68,000kNm.
Table 1. TBMs of more than 14m in diameter used and currently operating or on order for projects around the world
Start date/
Country Project
* = TunnelTalk reference article
See References below
TBM manufacturer Diameter
2017 Australia Melbourne West Gate Highway* 2 Herrenknecht EPBMs 15.6m
2018 China Nanjing MeiZiZhou Tunnel 1 Herrenknecht Mixshield
Ex-Nanjing Machine
2018 China Shanghai Zhou Jia Zui Road
River Crossing Motorway
1 Herrenknecht Mixshield 14.9m
2017 China Suai highway tunnel, Shantou* 1 CREG slurry TBM 15.3m
2017 China Shantou Su'Ai Sub-sea Tunnel East 1 Herrenknecht Mixshield 14.96m
2017 China Shenzhen highway tunnel* 1 CREG slurry TBM 15.8m
2017 Japan Tokyo Outer Ring Road Kan-etsu to Tomei* 4 machines
1 Kawaski, 3 JIM
2017 China Shanghai Zhuguang Road Tunnel 1 Herrenknecht EPBM
Ex Auckland Waterview TBM
2016 China Shanghai Yanjiang A30 Motorway 2 Herrenknecht Mixshields
Ex Shanghai Changjiang under river project
2016 China Shanghai Bei Heng Motorway 1 Herrenknecht Mixshield 15.53m
2016 China Zhuhai Hengqin Tunnel 1 Herrenknecht Mixshield
Ex Shanghai Hongmei Road Tunnel TBM
2016 Italy Santa Lucia Highway Tunnel,
A1 near Firenze
1 Herrenknecht EPBM 15.87m
2015 Hong Kong Lung Shan Tunnel on Liantang
Highway Project*
1 NFM TBM 14.1m
2015 Hong Kong Tuen Mun - Chek Lap Kok
subsea highway link
2 Herrenknecht Mixshields
1 x17.6m, modified later to a
smaller diameter, plus 1 x 14m
2015 China Wuhan Metro road/metro river crossing* 2 Herrenknecht Mixshields 15.76m
2013 China Shouxhiou Lake Highway Tunnel 1 Herrenknecht Mixshield
Ex-Nanjing Machine
2013 Italy Caltanissetta highway tunnel, Sicily* 1 NFM Technologies EPBM 15.08m
2011 China Shanghai West Changjiang Yangtze River Road Tunnel 1 Herrenknecht Mixshield
Ex-Shanghai Changjiang highway Project
2013 New Zealand Waterview highway connection, Auckland* 1 Herrenknecht EPBM 14.41m
2011 USA Alaskan Way highway replacement tunnel* 1 Hitachi Zosen EPBM 17.48m
2011 China Weisan Road Tunnel, Nanjing* 2 IHI/Mitsubishi/CCCC slurry TBMs 14.93m
2012 China Shanghai Hongmei Road 1 Herrenknecht Mixshield 14.93m
2011 Italy A1 Sparvo highway tunnel* 1 Herrenknecht EPBM 15.55m
2010 Spain Seville SE-40 Highway Tunnels* 2 NFM Technologies EPBMs 14.00m
2010 China Hangzhou Qianjiang Under River Tunnel 1 Herrenknecht Mixshield Ex-Shanghai Changjiang highway tunnel Project 15.43m
2009 China Yingbinsan Road Tunnel, Shanghai 1 Mitsubishi EPBM Ex-Bund Tunnel machine 14.27m
2008 China Nanjing Yangtze River Tunnel* 2 Herrenknecht Mixshields 14.93m
2007 China Bund Tunnel, Shanghai 1 Mitsubishi EPBM 14.27m
2006 China Jungong Road Subaqueous Tunnel, Shanghai 1 NFM slurry shield Ex-Groenehart machine 14.87m
2006 China Shanghai Changjiang under river highway tunnel 2 Herrenknecht Mixshields 15.43m
2006 Canada Niagara Water Diversion Tunnel* 1 Robbins hard rock gripper TBM
Rebuilt Manapouri tailrace tunnel machine
2005 Spain Madrid Calle 30 Highway Tunnels 2 machines
1 Herrenknecht, 1 Mitsubishi
2004 Russia Moscow Silberwald Highway Tunnel 1 Herrenknecht Mixshield
Ex-Elbe project machine
2004 China Shangzhong Road Subacqueous Tunnel, Shanghai 1 NFM Technologies
Ex-Groenehart machine
2004 Japan Tokyo Metro 1 IHI EPBM 14.18m
2001 Russia Moscow Lefortovo Highway Tunnel* 1 Herrenknecht Mixshield
Ex-Elbe project machine
2000 The Netherlands Groenehart double-track rail tunnel 1 NFM Technologies 14.87m
1997 Germany Hamburg 4th Elbe River Highway Tunnel* 1 Herrenknecht Mixshield 14.2m
1994 Japan Trans Tokyo Bay Highway Tunnel* 8 machines
3 Kawasaki, 3 Mitsubishi, 1 Hitachi, 1 IHI
* TunnelTalk reference below.
Earlier news in the world of mega-TBM operation reported final breakthrough of the NFM 15.08m diameter EPBM after completing the second drive for the Italian twin tube Caltanissetta highway tunnel in Sicily in November 2017. Following financial difficulties experienced by NFM and it previous parent company NHI of China, leading to takeover of NFM by Mühlhäuser of Germany in February 2019, there are several NFM TBMs currently on the resale market, one of them being the maga machine used in Sicily. See the TunnelTalk Equipment Sales page to know more details of the NFM machine currently available for resale. See also the TunnelTalk Discussion Forum article by Lok Home, President and CEO of The Robbins Company asking the question Rebuilt TBMs - are they as good as new? and search our library Archive to read articles about projects that used rebuilt TBMs to take advantage of the financial and schedule positives offered by using rebuilt machines on tight programme projects.
Celebrations as NFM mega TBM finishes last bore for the Caltanissetta highway tunnel in Sicily' style='width:400px;float: left;

Celebrations as NFM mega TBM finishes last bore for the Caltanissetta highway tunnel in Sicily

In the news in February 2019, is proposal by authorities in St Peterburg to use a rebuilt Herrenknecht TBM to excavate a twin tube highway tunnel of two lanes in each, as an alternative to the super 19m diameter mega TBM bored tunnel for the Orlovsky highway project. The 19m diameter mega machine was in-design by Herrenknecht for the proposed project but the project was put on hold in 2007 when the cost of the single-tube mega-machine double-deck tunnel escalated to unacceptable levels for the St Petersburg regional government. Russia is further suffering from the trade sanctions imposed on the country by the United Nations following its military annexation of the Crimea region that was previously part of Ukraine, a topic that Martin Herrenknecht commented on in the TunnelTalk face-to-face interview article with him and his successor, his son, Martin-Devid.
To keep the record up to date, please do let us know via our Contact Us service of any new mega TBM projects in the planning and added to the discussion about the possible limitations or potential for TBMs of increasingly large dimension.
Mega TBM arrives in Melbourne - TunnelTalk, March 2019
Mega TBM success at Caltanissetta in Sicily - TunnelTalk, November 2017
Mega slurry TBM for Shenzhen highway link - TunnelTalk, September 2017
TBM u-turn and relaunch in Hong Kong - TunnelTalk, August 2017
Two mega-TBMs for Melbourne highway tunnel - TunnelTalk, April 2017
Single bore solution for LA freeway missing link - TunnelTalk, May 2017
Mega TBMs begin Tokyo ring road drives - TunnelTalk, May 2017
China's mega Hong Kong-Zhuhai-Macao sea link moves forward - TunnelTalk, June 2011
Bosphorus Eurasia highway TBM breaks through - TunnelTalk, August 2015
Mega-EPBM for Italian highway tunnel - TunnelTalk, September 2016
Sparvo mega-TBM system available for new project - TunnelTalk, September 2014
Hong Kong awards major undersea highway - TunnelTalk, September 2013
Mega-TBMs for China double-deck link - TunnelTalk, May 2014
Video: Addressing Bertha's bearing seal issues in Seattle - TunnelCast, February 2014
'Yes' to bored tunnel alternative in Seattle - TunnelTalk, August 2011
Mega-TBM order is NFM's biggest ever - TunnelTalk, January 2013
Technical parameters of Seattle's mega EPBM - TunnelTalk, Dec 2012
Mega-EPBM naming ceremony at Hitachi Zosen - TunnelCast, December 2012
New Zealand joins the mega-TBM tunnelling set - TunnelTalk, August 2011
Russia confirms order for largest TBM ever - TunnelTalk, Aug 2011
A second mega-TBM river crossing for Nanjing - TunnelTalk, Aug 2011
Robbins TBM rolls into hard rock history - TunnelTalk, May 2011
Nanjing Highway Tunnels - TunnelTalk, Sept 2009
Seville SE-40 Highway Tunnels - TunnelTalk, April 2010
Giant TBM accepted and heading for Italy - TunnelTalk, Dec 2010
Seattle Alaskan Way bored highway tunnel - TunnelTalk, Oct 2009
Speedy mega TBM for Moscow Lefortovo highway - TunnelTalk, Oct 2002
4th Elbe tube inspires cutting edge technology - TunnelTalk, Jan 2000
Tokyo Bay highway engages eight mega TBMs - TunnelTalk, August 1994


UK contributor, name withheld by request

It is hard to say when the era of the mega-machine started. There was a time when 10m in diameter was considered the largest likely, or indeed possible. But whatever was once considered the technological limit for the size of TBMs, there are now many dozens of machines exceeding the 10m diameter size. This, of course, increases the benchmark for current mega-machine criteria. The need for ever-larger diameters is driven by the demand for ever-larger diameter tunnels able to incorporate extra and wider traffic lanes for heavy freight trucks as well as cars. Larger diameter bores are also needed to accommodate the latest in multi-modal transportation tunnels which will house both road and rail services as well as pedestrian and cycle-ways and perhaps also utility corridors.

Discussions in the past have considered the manufacture of the main bearing a limiting factor but these can now be designed and delivered in sections. Precision machining and welding has these vital components of the new mega-machines completed and built into them on site. A limit to the size and load of a single component to job sites was also considered a controlling barrier but first time on-site assembly, as promoted by Robbins in particular, overcomes some of these limitations.

Another consideration, as explained by Yasunori Kondo San at Kawasaki in Japan, is application of the thrust needed to advance such mega machines. For soft ground TBMs this force is applied directly to the precast concrete segments of the tunnel lining. These, as well as the number and size of the thrust rams around the perimeter of the machines, must be designed to take and deliver the powerful forces needed to move a mega-machine forward. There is a controlling factor on the number and power of the thrust rams needed to apply the force, as well as the surface area and ability of the precast concrete lining segments to accept the load.

Other considerations will be explored and added to the Discussion Forum as they are contributed.

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