英吉利海峡隧道简介中文英文对照

Channel Tunnel英吉利海峡隧道The Channel Tunnel (French: Le tunnel sous la Manche), also known by the portmanteau Chunnel1, is a 50.5-kilometre (31.4 mi) undersea rail tunnel linking Folkestone, Kent in England with Coquelles near Calais in northern France beneath the English Channel at the Strait of Dover. At its lowest point it is 75 m (250 ft) deep.2 The Channel Tunnel has the longest undersea portion of any tunnel in the world, but the Seikan Tunnel in Japan is both longer and deeper overall, at 53.85 kilometres (33.5 mi) and 240 metres (790 ft) respectively.英吉利海峡隧道（法国称之为拉芒什海峡隧道），又称英法海底隧道或欧洲隧道，是一条横贯英法之间多佛海峡的海底铁路隧道，它西起英国的福克斯特（Folkestone）和肯特（Kent），东至法国北部加来（Calais）附近的考克莱尔（Coquelles），全长50.5km。英吉利海峡隧道最低点75m深，其海底部分为世界最长，总长度也仅次于日本的青函海底隧道，青函海底隧道长53.85km，埋深为240m。The tunnel carries high-speed Eurostar passenger trains, Eurotunnel ro-ro vehicle transport and international rail freight trains. In 1996 the American Society of Civil Engineers identified the tunnel as one of the Seven Wonders of the Modern World.隧道中运行的火车有“欧洲之星”高速旅客列车、装载公路车辆的区间列车、以及国际铁路货运列车。美国土木工程学会1996年称之为现代世界的七大奇迹之一。Surveying undertaken in the 20 years before tunnel construction confirmed earlier speculations that a tunnel route could be bored through a chalk marl stratum. The chalk marl was conducive to tunnelling, with impermeability, ease of excavation and strength. While on the English side the chalk marl ran along the entire length of the tunnel, on the French side a length of 5 kilometres (3 mi) had variable and difficult geology. The Channel Tunnel consists of three bores: two 7.6-metre (25 ft) diameter rail tunnels, 30 metres (98 ft) apart, 50 kilometres (31 mi) in length with a 4.8-metre (16 ft) diameter service tunnel in between. There are also cross-passages and piston relief ducts. The service tunnel was used as a pilot tunnel, boring ahead of the main tunnels to determine the conditions. English access was provided at Shakespeare Cliff, while French access came from a shaft at Sangatte. The French side used five tunnel boring machines (TBMs), the English side used six. The service tunnel uses Service Tunnel Transport System (STTS) and Light Service Tunnel Vehicles (LADOGS). Fire safety was a critical design issue. 在隧道建设之前，进行了20年的勘测工作，勘测发现隧道线路将穿过一层泥灰质白垩岩地层。泥灰质白垩岩由于不透水、易于开挖，且具有一定的强度，因此有利于隧道的修建。隧道线路靠近英国一侧均为泥灰质白垩岩地层，而靠近法国一侧则存在一段长5km的复杂多变地层。英吉利海峡隧道由三条隧洞组成，其中两条为直径7.6m的铁路隧洞，长50km，两洞相距30m，另一条为直径4.8m的后勤服务洞，其处于两条铁路隧洞之间。另外设置有横通道和活塞压力调解洞。后勤服务洞也作为先导洞使用，以便在主洞开挖之前确定主洞的地质条件。隧道在英国一侧由莎士比亚陡崖（Shakespeare Cliff）进入，在法国一侧由位于桑加特（Sangatte）隧洞进入。法国一侧采用了五台隧道掘进机（TBM），英国一侧采用了六台TBM。后勤服务洞使用了服务隧道运输系统（STTS）和轻型服务隧道运输车（LADOGS）。消防安全是一个关键的设计问题。Between the portals at Beussingue and Castle Hill the tunnel is 50.5 kilometres (31 mi) long, with 3.3 kilometres (2 mi) under land on the French side, 9.3 kilometres (6 mi) under land on the UK side and 37.9 kilometres (24 mi) under sea.51 This makes the Channel Tunnel the second longest rail tunnel in the world, behind the Seikan Tunnel in Japan, but with the longest under-sea section.52 The average depth is 45 metres (148 ft) below the seabed.53 On the UK side, of the expected 5 million m of spoil approximately 1 million m was used for fill at the terminal site, and the remainder was deposited at Lower Shakespeare Cliff behind a seawall, reclaiming 74 acres (30 ha)5 of land.54 This land was then made into the Samphire Hoe Country Park. Environmental impact assessment did not identify any major risks for the project, and further studies into safety, noise, and air pollution were overall positive. However, environmental objections were raised over a high-speed link to London.55隧道从Beussingue入口至Castle Hill出口，总长50.5km，其中法国一侧的陆地长度3.3km，英国一侧的陆地长度9.3km，海底长度37.9km。英吉利海峡隧道为世界上第二长的铁路隧道，仅次于日本的青函海底隧道，但是其海底段却是世界最长的。隧道的平均埋深为45m（海床面以下）。在英国一侧开挖的土石方约为500 m3，其中约100 m3用于填埋转运码头（terminal site），其余部分堆放于莎士比亚陡崖的低洼处，这将填埋出一个面积约74英亩的陆地，这块陆地已改造成Samphire Hoe郊外公园。环境影响评价的结果表明本工程不会出现重大环境问题，进一步的研究也表明本工程的安全、噪音、大气污染处于总体可控的水平。当然，与伦敦之间的高速连接对环境的影响也存在一些争议。edit Surveying勘测Marine soundings and samplings by Thom de Gamond were carried out during 183367, establishing the seabed depth at a maximum of 55 m and the continuity of geological strata (layers). Surveying continued over many years, with 166 marine and 70 land-deep boreholes being drilled and over 4000 line kilometres of marine geophysical survey completed.56 Surveys were undertaken in 195859, 196465, 197274 and 198688.Thom de Gamond于1833年至1867年间完成了海洋深度量测和取样工作，绘制了海床深度和地层剖面图。勘测工作持续了很多年，完成了166个海洋钻孔和70个陆地深井钻孔，以及4000条数千米长的海洋地球物理勘测。勘测工作分别于1958-1959，1964-1965，1972-1974，和1986-1988年间进行。The surveying in 195859 catered for immersed tube and bridge designs as well as a bored tunnel, and thus a wide area was investigated. At this time marine geophysics surveying for engineering projects was in its infancy, with poor positioning and resolution from seismic profiling. The 1964-65 surveys concentrated on a northerly route that left the English coast at Dover harbour, using 70 boreholes an area of deeply weathered rock with high permeability was located just south of Dover harbour.561958-1959年间完成的勘测工作主要是为了进行沉管隧道、桥梁和海底开挖隧道三种方案的必选，因此，勘测范围较大。当时，海洋地球物理勘测技术应用于工程上还处于初期阶段，地震剖面的布置和分辨率都较差。1964-1965年完成的勘测工作集中于北线方案，其位于英国多佛港的左侧海岸线，在多佛港的南侧布置了70个钻孔，钻孔揭露的主要为具有高透水性的强风化岩石。Given the previous survey results and access constraints a more southerly route was investigated in the 197273 survey and the route was confirmed to be feasible. Information for the tunnelling project also came from work before the 1975 cancellation. On the French side at Sangatte a deep shaft with adits was made. On the English side at Shakespeare Cliff the government allowed 250 metres (820 ft) of 4.5 metres (15 ft) diameter tunnel to be driven. The actual tunnel alignment, method of excavation and support were essentially the same as the 1975 attempt. In the 198697 survey, previous findings were reinforced and the nature of the gault clay and tunnelling medium, chalk marl that made up 85% of the route, were investigated. Geophysical techniques from the oil industry were employed.56在已有勘测结果的基础上，1972-1973对南线方案进行了调查，调查结果证实南线方案是可行的。在法国Sangatte开挖了一个较深的竖井，英国政府也批准了在莎士比亚陡崖处开挖一个直径4.5m深250m的隧洞。实际开挖的隧道的线路布置、开挖方法和设计方案与1975年的实验洞基本上是一样的。1986-1997年的勘测结果证实了之前的调查结论，勘测期间对隧道沿线的泥灰质粘土、泥灰质白垩岩（隧道线路85%以上为泥灰质白垩岩）以及隧道的地质环境进行了调查。此次勘测聘请了石油工业的地球物理技术人员。edit Geology地质Geological profile along the tunnel as constructed. For the majority of its length the tunnel bores through a chalk marl stratum (layer).隧道沿线的地质条件：隧道沿线大部分为泥灰质白垩岩地层。Successful tunnelling under the channel required a sound understanding of the topography and geology and the selection of the best rock strata to tunnel through. The geology generally consists of northeasterly dipping Cretaceous strata, part of the northern limb of the Wealden-Boulonnais dome. Characteristics include:海底隧道能否成功修建，关键在于对海底地形地貌和地质条件的全面了解并据此选择隧道的最佳地层。沿线地层主要为倾向北东的白垩纪地层，少部分为Wealden-Boulonnais穹地的北翼地层。其主要特征如下：as observed by Verstegan in 1698, the chalk of the cliffs on either side of the Channel is continuous, and contains no major faulting 根据Verstegan1698年的调查，海峡两岸陡崖上的白垩地层是连续的，其间不存在大型断裂。the cliffs consist of four geological strata, marine sediments laid down 90100 million years ago; pervious upper and middle chalk above slightly pervious lower chalk and finally impermeable Gault Clay. A sandy stratum, glauconitic marl (tortia), is in between the chalk marl and gault clay 两岸陡崖主要由四个地层组成。九千万年至一亿年前的海洋沉积地层、强透水的早、中白垩地层、弱透水的晚白垩地层、以及不透水的泥灰质粘土层。白垩地层与泥灰质粘土层之间为砂质地层，岩性为含海绿石的泥灰岩。a 2530 metre (8298 ft) layer of chalk marl (French: craie bleue)57 in the lower third of the lower chalk appeared to present the best tunnelling medium. The chalk has a clay content of 3040% providing impermeability to groundwater yet relatively easy excavation with strength allowing minimal support. Ideally the tunnel would be bored in the bottom 15 m of the chalk marl, allowing water inflow from fractures and joints to be minimised, but above the gault clay that would increase stress on the tunnel lining and swell and soften when wet.在晚白垩地层中存在一层厚度为25-30m的泥灰质白垩岩，该层最适合于开挖隧道。该白垩地层中粘土含量为3040%，其渗透性差，可以阻止地下水渗透到隧道中，而且该地层较易开挖，又具有一定的强度，较少的支护即能保持隧道的稳定。隧道可以设置在底部15m厚的泥灰质白垩岩，这样可以使通过裂隙和节理渗透到隧道中的地下水减少到最低水平。隧道必须位于泥灰质粘土层的以上，因为泥灰质粘土会增加隧道衬砌上的压力，同时遇水易发生膨胀和软化。On the English side of the channel the strata dip less than 5, however on the French side this increases to 20. Jointing and faulting is present on both the English and French sides. On the English side only minor faults of displacement less than 2 metres (7 ft) exist. On the French side displacements of up to 15 metres (49 ft) are present owing to the Quenocs anticlinal fold. The faults are of limited width, filled with calcite, pyrite and remoulded clay. The increased dip and faulting restricted the selection of route on the French side. To avoid confusion microfossil assemblages were used to classify the chalk marl. On the French side, particularly near the coast, the chalk was harder and brittler and more fractured than on the English side. This led to the adoption of different tunnelling techniques on the French and English sides.58英国一侧地层的倾角小于5，但至法国沿岸，地层倾角已增加至20。英国和法国地层中都存在节理和断层。英国一侧的断层规模较小，错动距离小于2m。法国一侧断层的错动距离达到15m，其主要是由Quenocs背斜引起的。断层带宽度较小，充填有方解石、黄铁矿、重塑黏土。地层倾角的增加和断层的存在使法国一侧线路选择较为困难。为了避免误判，采样了微化石采样对泥灰质白垩岩进行分类。法国一侧的白垩地层比英国一侧的白垩地层更坚硬、更脆、也更破碎。这导致了英法两侧采用了不同的隧道开挖技术。No major geological hazards were identified, however the Quaternary undersea valley Fosse Dangaered, and Castle Hill landslip located at the English portal were concerning. Identified by the 196465 geophysical survey the Fosse Dangaered is an infilled valley system extending 80 metres (262 ft) below the seabed, 500 metres (1,640 ft) south of the tunnel route, located mid-channel. A 1986 survey showed that a tributary crossed the path of the tunnel and so the tunnel route was made as far north and deep as possible. The English terminal had to be located in the Castle Hill landslip, which consists of displaced and tipping blocks of lower chalk, glauconitic marl and gault debris. Thus the area was stabilised by buttressing and inserting drainage adits.58 The service tunnels were pilot tunnels preceding the main tunnels so that the geology, areas of crushed rock and zones of high water inflow could be predicted. Exploratory probing took place in the service tunnels in the form of extensive forward probing, vertical downward probes and sideways probing.58除了第四纪的海底峡谷Fosse Dangaered，以及位于英国隧道进口的Castle Hill滑坡以外，隧道沿线未发现其它大型的不良地质作用。1964-1965年完成的地球物理勘测表明，Fosse Dangaered海底峡谷由第四纪沉积物填充，延伸至海床面以下80m，位于英吉利海峡中部，隧道线路以南500m。1986年完成的勘测结果显示，Fosse Dangaered海底峡谷有一条支脉穿过隧道线路，因此，隧道选线时尽量往北移，同时埋深尽可能加大。隧道在英国一侧的进出口只能选择在Castle Hill滑坡体中，滑坡体由经过错动的白垩纪晚期白垩岩、海绿石泥灰岩和泥灰质粘土组成。因此，这一区域增加了一个支洞进行加固。位于两条主洞之间的服务洞也作为超前探洞，以便查明主洞开挖前方的地质条件、破碎岩体的分布、以及可能出现涌水的位置。服务洞内进行了大量的勘探工作，包括大范围的超前勘探、垂直向下的勘探、以及边墙两侧方向的勘探。edit Tunnelling隧道开挖Typical tunnel cross section, with a service tunnel in between twin rail tunnels. Shown linking the rail tunnels is a piston relief duct, necessary to manage pressure changes due to the movement of trains.典型的隧道横断面图，包括两条铁路主洞，以及中部的服务洞。图中连接两条铁路主洞是一条活塞压力调节洞，用于调节由于火车活塞式运行而产生的空气压力。Tunnelling between England and France was a major engineering challenge with the only precedent being the undersea Seikan Tunnel in Japan. A serious risk with underwater tunnels is major water inflow due to the water pressure from the sea above under weak ground conditions. The Channel Tunnel also had the challenge of time - being privately funded, early financial return was paramount.英法之间隧道的开挖是本项目的主要难点，除了日本的青函海底隧道，无其它先例。水下隧道面临的主要风险是海水沿着破碎带在水压力下进入隧道。英吉利海峡隧道也面临着工期紧迫的问题，因为吸引了大量私人投资，因此尽早收回投资是至关重要的。The objective was to construct: two 7.6-metre (25 ft) diameter rail tunnels, 30 metres (98 ft) apart, 50 kilometres (31 mi) in length; a 4.8-metre (16 ft) diameter service tunnel between the two main tunnels; pairs of 3.3-metre (11 ft) diameter cross-passages linking the rail tunnels to the service tunnel at 375-metre (1,230 ft) spacing; piston relief ducts 2-metre (7 ft) diameter connecting the rail tunnels at 250-metre (820 ft) spacing; two undersea crossover caverns to connect the rail tunnels.59 The service tunnel always preceded the main tunnels by at least 1 kilometre (0.6 mi) to ascertain the ground conditions, experience with tunnelling through chalk had occurred in the mining industry. The undersea crossover caverns were a complex engineering problem. The French cavern was based on the Mount Baker Ridge freeway tunnel in the USA. The UK cavern was dug from the service tunnel ahead of the main tunnels to avoid delay.主要构筑物包括：两条长50km、直径7.6m、相隔30m的铁路主洞；一条位于两条主洞之间的直径4.8m的服务洞；主洞和服务洞每隔375m设置两条3.3m的横通道连接；两条主洞每隔250m设置一条直径2m的活塞压力调节洞相互连通；两个位于水下的用于连接铁路主洞的渡线洞。服务洞必须超前主洞最少1km，以便探查主洞前方的地质条件。白垩岩的开挖经验主要来自于采矿行业。水下调度室的修建是一个复杂的工程问题。法国一侧的水下调度室的修建参考了美国Mount Baker Ridge高速公路隧道资料。英国一侧的水下调度室是在服务洞的基础上扩挖的，以便节省工期。Precast segmental linings in the main TBM drives were used, but different solutions were used on the English and French sides. On the French side neoprene and grout sealed bolted linings made of cast iron or high-strength reinforced concrete were used. On the English side the main requirement was for speed, and bolting of cast-iron lining segments was only carried out in areas of poor geology. In the UK rail tunnels eight lining segments plus a key segment were used, on the French side five segments plus a key segment.60 On the French side a 55-metre (180 ft) diameter 75-metre (246 ft) deep grout-curtained shaft at Sangatte was used for access. On the English side a marshalling area was 140 metres (459 ft) below the top of Shakespeare Cliff, and the New Austrian Tunnelling method (NATM) was first applied in the chalk marl here. On the English side the land tunnels were driven from Shakespeare Cliff, the same place as the marine tunnels, not from Folkestone. The platform at the base of the cliff was not large enough for all of the drives, and despite environmental objections tunnel spoil was placed behind a reinforced concrete seawall, on condition of placing the chalk in an enclosed lagoon to avoid wide dispersal of chalk fines. Owing to limited space the precast lining factory was on the Isle of Grain in the Thames estuary.59隧道采用TBM开挖，预制拼装管片衬砌支护，但是英国和法国两侧采用了不同的施工技术。法国一侧采用了由高强度钢筋混凝土制作而成的氯丁橡胶密封管片衬砌，而在英国一侧，为加快速度，钢筋锚固的管片衬砌仅地质条件较差的地段。英国一侧的隧道衬砌采用八块拼装管片和一块关键管片组成，而法国一侧的隧道衬砌采用五块拼装管片和一块关键管片组成。在法国一侧的Sangatte采用了一个直径55m深75m注浆帷幕洞作为入口。英国一侧的入口位于莎士比亚陡崖下方140m，首次采用了新奥法（NATM）开挖本地的泥灰质白垩岩。在英国一侧，陆地隧道和海底隧道均从莎士比亚陡崖开始开挖。由于陡崖的平台不够宽大，因此将隧道开挖的碎渣堆放在一个钢筋混凝土衬砌的海堤后方，以便增大施工平台，尽管一些环境保护人士对此提出了异议。由于施工空间的限制，预制拼装管片生产工厂选在Thames的格兰岛。On the French side, owing to the greater permeability of water, earth pressure balance TBMs with open and closed modes were used. The TBMs were of a closed nature during the initial 5 kilometres (3 mi) but then operated as open, boring through the chalk marl stratum.59 This minimised the impact to the ground and allowed high water pressures to be withstood, and it also alleviated the need to grout ahead of the tunnel. The French effort required five TBMs: two main marine machines, one main land machine (the short land drives of 3 km allowed one TBM to complete the first drive then reverse direction and complete the other), and two service tunnel machines. On the English side the simpler geology allowed faster open-faced TBMs.61 Six machines were used, all commencing digging from Shakespeare Cliff, three marine bound and three for the land tunnels.59 Towards the completion of the undersea drives the UK TBMs were driven steeply downwards and buried clear of the tunnel. The French TBMs then completed the tunnel and were dismantled.62 A 900 mm gauge railway was used on the English side during construction.63在法国一侧，由于地层透水性更强，因此采用了具有开敞式和封闭式两种模式的土压平衡盾构掘进机，隧道最开始的5km段采用封闭模式，到达泥灰质白垩岩地层则采用开敞模式，这样可以减少衬砌结构承受的围岩压力和高水压，同时也可减少隧道顶部的注浆需求。法国一侧采用了5台TMB，其中2台用于两条主洞海底部分的开挖，1台用于主洞陆地部分的开挖（陆地部分的主洞仅3km长，因此，TBM完成一个主洞的开挖后可调转方向开挖另一个主洞），2台用于服务洞的开挖。英国一侧由于地质条件简单，因此可采用开挖速度更快开敞式TBM，一共采用了6台TBM，均从莎士比亚陡崖处开始开挖，其中3台用于海底部分的开挖，3台用于陆地部分的开挖。在英法两国的TBM衔接处，英国一侧的TBM采用大角度向下开挖并最终埋没在隧道的下方，法国一侧的TBM完成衔接处剩余段的开挖后，拆卸运出洞外。英国一侧隧道的施工中采用了900mm轨距的轨道运输。edit Railway design and rolling stock 铁路设计及运输工具 Interior of Eurotunnel Shuttle, a vehicle shuttle train. The largest railway wagons in the world,5 the shuttle trains transport vehicles between terminals either side of the tunnel.上图为英吉利海峡隧道通勤列车内部照片，这是一种装载各种机动车通勤列车，它拥有世界上最大的铁路列车车厢，用于装载隧道两端的机动车辆。 There are three communication systems in the tunnel: concession radio (CR) for mobile vehicles and personnel within Eurotunnels Concession (terminals, tunnels, coastal shafts); track-to-train radio (TTR) for secure speech and data between trains and the railway control centre; Shuttle internal radio (SIR) for communication between shuttle crew and to passengers over car radios.64 All tunnel services run on electricity, shared equally from English and French sources. Power is delivered to the locomotives via an overhead line (catenary).65 A cab signalling system is used that gives information directly to train drivers on a display. There is automatic train protection (ATP) that stops the train if the speed differs from that indicated on the in-cab display. TVM430, as used on TGV Nord, is used in the tunnel. 66 The American Sonneville International Corporation track system was used in the tunnel, ballasted track was ruled out owing to maintenance constraints and a need for geometric stability. The Sonneville system has UIC60 rails on 900A grade resting on microcellular EVA pads, bolted into concrete. 67隧道内有3套通信系统：CR通讯：用于在英吉利海峡隧道大范围内（包括火车站、隧道内部和光线杆的沿线）的移动交通工具和工作人员的无线通讯；TTR通讯：用于在火车和铁路控制中心之间的通话和数据传输的火车追踪无限通讯；SIR通讯：用于往返列车机组人员以及乘客之间的列车内部的无线通讯。所有的隧道设施均采用电力做为动力，电力由英国和法国均摊，电力通过列车上部的架空输电线路传送到列车的机车上。一个司机台信号系统用来给火车驾驶员直接发送信息于在司机台显示屏幕上。当行驶速度不同于驾驶室内屏幕上显示的速度时，有一个列车自动超速防护(ATP)系统会停止火车运行。TVM430，被用作高速列车（TVG）Nord，在隧道内使用。隧道内使用美国松那飞国际合作示踪系统，平稳跟踪器用来维持限制物和保证几何稳定性的需要。松那飞系统有UIC60 900A级别的铁轨，依靠微孔EVA垫，栓进混凝土里。Initially 38 Le Shuttle locomotives were commissioned, working in pairs with one at each end of a shuttle train. The shuttles have two separate halves: single and double deck. Each half has two loading/unloading wagons and 12 carrier wagons. Eurotunnels original order was for 9 shuttles. 46 Class 92 locomotives for hauling freight and overnight passenger trains were commissioned, which can run on both overhead AC and third-rail DC power. Freight shuttles also have two halves, with each half containing one loading wagon, one unloading wagon and 14 carrier wagons. There is a club car behind the leading locomotive. Eurotunnel originally ordered 6 freight shuttles. 31 Eurostar trains, based on the French TGV with many modifications for safety within the tunnel, were commissioned, with split ownership between British Rail, French National Railway Company and National Railway Company of Belgium. British Rail ordered seven more for services north of London.68最初采用了38辆Le往返机车，每列通勤火车的头部和尾部各设一辆机车牵引。每列通勤火车都有前后两个独立的部分组成，每个部分都有2节装卸车厢和12节载货车厢组成。 隧道运营公司最初订购了九列通勤火车。订购了92辆46级的机车头用来牵引货物和旅客列车，这些机车头可使用列车顶部的交流电和直流电。载货通勤列车也由前后两部份组成，每部分有一节装载车厢，一节卸载车厢和14节货物车厢。 隧道运营公司最初订购了6列载货通勤火车和31辆欧洲之星高速火车。欧洲之星是在法国TGV高速火车的基础上，根据隧道内运营安全的需要改装而成。隧道运营公司的股份由英国铁路公司、法国国家铁路公司和比利时国家铁路公司共同所有。 英国铁路公司另外订购了七列欧洲之星高速火车服务于伦敦北部地区。edit Services 服务The service tunnel is used for access to technical equipment in cross-passages and equipment rooms, to provide fresh-air ventilation, and for emergency evacuation. The Service Tunnel Transport System (STTS) allows fast access to all areas of the tunnel. The service vehicles are rubber-tyred with a buried guidance wire system. 24 STTS vehicles were made, and are used mainly for maintenance but also for firefighting and in emergencies. Pods with different purposes, up to a payload of 2.55 tonnes, are inserted into the side of the vehicles. The STTS vehicles cannot turn around within the tunnel, and are driven from either end. he maximum speed is 80 km/h (50 mph) when the steering is locked. A sma