Hex River Tunnel

Hex River Pass
Western access to the 13.5 km long tunnel 4 as seen from the Salbar service station .
Route length:	1877: 39.1 km 1921: 38.6 km 1989: 31.2 km
Gauge :	1067 mm ( cape track )
Maximum slope :	1877: 25 ‰ from 1989: 15  ‰
Minimum radius :	1877: 100 m from 1943: 200 m
Legend De Doorns of Cape Town Hex River Tunnel 1 (483 m) Almeria from 1989 Hex River Tunnel 2 (1100 m) Osplaas 1878-1989 left: 1878-1921 right: 1921–1989 Hex River Tunnel 3 (1200 m) tunnel 1921-1989 Salbar from 1989 Hex River Tunnel 4 (13,500 m) Matroosberg 1931-1989 Hexton from 1989 left: 1931–1989 right: 1878–1989 Kleinstraat to Johannesburg

The Hex River Tunnels , English Hex River Tunnels , are four successive railway tunnels in the Western Cape Province of South Africa , which cross under the Hex River Mountains . You are on the 31.2 km long single-track section De Doorns - Kleinstraat on the Cape Town - Johannesburg connection . The longest is the 13.5 km long Hex River Tunnel 4 , which is the second longest railway tunnel in South Africa after the Gautrain tunnel . The entire section was put into operation on November 27, 1989 and replaced the old line built in 1878 over the Hex River Pass.

Old route over the Hex River Pass

Hex River Pass Tunnel
East portals of the tunnels on the Hex River Pass route: on the left the tunnel from 1876, on the right the tunnel from 1929
Coordinates
West portal 1877	33 ° 26 ′ 41 ″  S , 19 ° 45 ′ 28 ″  E
East portal 1877	33 ° 26 ′ 40 ″  S , 19 ° 45 ′ 34 ″  E
West portal 1929	33 ° 26 ′ 41 ″  S , 19 ° 45 ′ 27 ″  E
East portal 1929	33 ° 26 ′ 37 ″  S , 19 ° 45 ′ 32 ″  E

The Cape Fold Belt separates Cape Town on the coast from the hinterland and thwarted first attempts to expand the Cape Colony's railway network inland. The Cape Colony government decided in 1872 to build a railway line to Kimberley , where diamonds had been found in 1866 . She was supposed to climb the mountain range near the Hex River Mountains. The Cape Government Railways (CGR) were founded to build the line, which resulted from the merger of four nationalized private railways in the Cape Town region. The railway engineer Thomas Brounger was commissioned to supervise the construction work .

Routing

In 1874, the surveyor Wells Hood determined a possible route from De Doorns in the Hex River Valley to the Karoo plateau east of the valley. The route should overcome the 480 m difference in altitude from De Doorms to the apex at Matroosberg and back down to Kleinstraat with a maximum gradient of 25 ‰. The smallest curve radius should be 100 m and a short tunnel was planned.

The route suggested by Thomas Brounger led from De Doorns via Osplaas, where the only crossing station was located, to the culmination point at 959 m at Matroosberg and then via Kleinstraat on to Touws River . The route was approved in 1876 and put into operation in 1877.

The construction of the line was quick and relatively inexpensive. This route was in operation for more than a hundred years. It was a key point to enable the first railway connection from the coast to the Witwatersrand area and a prerequisite for the colonization of inner South Africa, which Cecil Rhodes had promoted .

Cape Track

Three- rail track at the old level crossing over Strand-Straße at Cape Town train station

The first railway line between Cape Town and Wellington was built in standard gauge - a gauge that seemed unsuitable because of the narrow curves of the planned route over the Hex River Pass. The CGR therefore decided to run the route over the pass in the narrower cape gauge and to install a third rail on the existing routes . Ultimately, the CGR decided to convert all standard gauge lines to Cape gauge. It is thanks to the Hex River Pass that most of the railway lines in South Africa are in Cape Gauge.

First tunnel

This first stretch of the Hex River Pass had a 180 m long tunnel 34 km from De Doorns - the first railway tunnel in South Africa. The straight tunnel has brick portals, but has no cladding inside.

Second tunnel

The first tunnel on the Hex River Pass route was in operation for 53 years. In 1929 the line was straightened so that larger locomotives could be used. For this purpose, a new tunnel had to be built, which was lined with concrete. As an additional crossing point to the existing Osplaas train station, another crossing station called Tunnel was set up east of the tunnel . It consisted of two stub tracks in which the trains could be parked until the opposing trains had crossed - the stub tracks branched off from the main line on both sides and, despite the mountainous area, had no gradient. The second Hex River tunnel was in operation until the line over the pass was closed in 1989.

Hexton Tunnel System

Hexton Tunnel System
place	Breede Valley
cross-section	Normal cross-section: 30 m² Hexton crossing station: 60 m²
construction
Client	South African Railways
start of building	1946/1974/1980
business
operator	Transnet Freight Rail
release	1976 tunnel 1 1989 tunnel 3–4
map
Hexton Tunnel System and old route over the pass
Coordinates
De Doorns	33 ° 28 ′ 56 ″  S , 19 ° 39 ′ 57 ″  E
Kleinstraat	33 ° 23 ′ 43 ″  S , 19 ° 57 ′ 21 ″  E

Hex River Tunnel 1-3
West portal of tunnel 1. Only one tube of the double tunnel is in operation.
length	Tunnel 1: 484 m, Tunnel 2: 1100 m, Tunnel 3: 1200 m
Coordinates
West portal 1	33 ° 28 ′ 36 ″  S , 19 ° 40 ′ 18 ″  E
East portal 1	33 ° 28 ′ 23 ″  S , 19 ° 40 ′ 29 ″  E
West portal 2	33 ° 27 ′ 0 ″  S , 19 ° 42 ′ 45 ″  E
East portal 2	33 ° 26 ′ 34 ″  S , 19 ° 43 ′ 14 ″  E
West portal 3	33 ° 25 ′ 28 ″  S , 19 ° 44 ′ 18 ″  E
East portal 3	33 ° 24 ′ 53 ″  S , 19 ° 44 ′ 38 ″  E

With the exception of the Hex River Pass, the railway line between Cape Town and Beaufort West has a decisive gradient of 15 ‰ and a minimum curve radius of 200 m. After arches were straightened in 1943, the pass route had the same curve radii as the rest of the route, but the 25 ‰ gradients were still an operational obstacle: long trains had to be divided and additional locomotives were needed to move the trains over the Carrying Passport. This operational bottleneck could only be eliminated with extensive measures.

WH Evans, future superstructure engineer for South African Railways (SAR), proposed a route between De Doorns and Kleinstraat with four tunnels, the longest being 13.5 km long. This allowed the gradient to be limited to 15 ‰ and the curve radii could be kept greater than 800 m. The construction costs were justified by the considerable savings in operating costs: the new route is eight kilometers shorter than the route over the Hex River Pass. Bends with an added angle of 5280 ° and slopes with a total height of 110 m were avoided. Travel times have been reduced by 23 minutes in the direction of Beaufort West and 36 minutes in the direction of Cape Town. It was also possible to save the locomotives and their personnel required for mountain route operations.

First construction work

Original east portal of Hex River Tunnel No. 4, abandoned in 1948.

The project was approved in 1946. The driving of the longest tunnel should begin with full excavation from both sides at the same time. It was planned that in this way 3.5 km of tunnel including lining could be built annually, so that the tunnel would have been completed after four years.

Work on the shorter tunnels and the rest of the earthworks began immediately, but delays occurred on the longest tunnel because the special equipment required had to be designed and ordered first. While waiting for the delivery of the devices, a 20 m long piece of the tunnel tube according to the Belgian construction method could be built from the west and east portal by the end of 1948 . The east portal was constructed approximately 15 km west of the Touws River immediately adjacent to National Route 1 . The route should be led here in a cut until the required depth for the tunnel was reached.

First postponement of the project

In April 1950, work on the new line was postponed for economic reasons. Instead, the existing route over the Hex River Pass was electrified in 1954 and class 4E electric locomotives were used. When the work was stopped, a total of 1170 m of tunnel had been excavated and 540 m of concrete lining had been installed in the shorter tunnel.

Second and third postponement of the project

Work on the tunnel was resumed for a short time in 1965, but was suspended again in the same year. They were resumed in 1974 and now also include a redesign of the lower part of the old route between De Doorns and Osplaas, as well as the construction of tunnel 1. This tunnel was built with two tubes, but only one of them was put into operation in 1976. The completion of the whole route was stopped again due to financial problems. It was not released for completion until the end of 1979, after the performance of the line was checked with the aid of graphic timetables and computer-aided train route calculations.

Completion of the Hexton tunnel system

In most respects, the project was completed after planning in 1945. After reviewing the performance of the line, it was decided to build an additional Hexton crossing station in the middle of tunnel 4 in addition to the already planned Almeria crossing stations between tunnels 1 and 2 and Salbar between tunnels 3 and 4 . The capacity of the route between De Doorns and Kleinstraat has been increased from 31 to 42 trains per day.

construction

When tendering the contracts, two routes were suggested for the long tunnel 4:

• a straight route, which roughly followed the original project, but whose east portal was further away from the N1
• an arched one that lies in shale and would have made the use of a tunnel boring machine economically viable.

The offers were also obtained for a circular or horseshoe-shaped tunnel cross-section with a concrete or shotcrete lining. After examining the technical, geological and economic aspects, the straight version with a horseshoe-shaped profile and concrete lining was chosen.

The tunnel was built by Compagnie Interafricaine De Travaux (Comiat), a division of Spie Batignolles from Paris.

The contract for the construction of tunnel 4 was awarded on August 13, 1980 at an offer price of 26,770,082 rand . Completion should first take place on August 12, 1984, but was then postponed to February 25, 1986. The preparatory work began in September 1980 and the excavation in January 1981. However, due to unforeseen poor subsoil conditions, the tunnel could not be completed until November 1988.

Tunnels 2 and 3 are similar in structure to the long tunnel, but were built as part of a separate contract at a cost of R9 million. Both tunnels were partially excavated when the work was stopped in 1949 - the 1.1 km long tunnel 2 over a length of 583 m, the largest part of which was lined with concrete, the 1.2 km long tunnel 3 over a length of 467 m , only the places in the unstable rock were lined. The contract required the widening of both tunnels according to the new implementation guidelines so that electrification became possible and wider vehicle boundaries could be approved.

The four tunnels carried out have a total length of 16.3 km.

The new line was completed more than 40 years after the first excavation work in April 1989 and officially opened on November 27, 1989. It replaced the old route over the Hex River Pass, whose operation was thus suspended.

Tunnel 4

The passing track inside the tunnel 4

Hex River Tunnel 4
East portal
length	13.5 km
Largest coverage	250 m
construction
building-costs	26,770,082 rand (25 million euros )
Coordinates
West portal 4	33 ° 24 ′ 54 ″  S , 19 ° 45 ′ 53 ″  E
East portal 4	33 ° 24 ′ 30 ″  S , 19 ° 54 ′ 28 ″  E

The west portal of tunnel 4, which was built in 1948, lies on an almost vertical slope. The east portal lies at the end of a 600 m long and 16 m deep cut and a piece southeast of the portal built in 1948. The tunnel is 13.5 km long and has a maximum overburden of 250 m. The gradient is 15 ‰ except for the area of ​​the crossing station in the tunnel, where it has been reduced to 5 ‰. Five ventilation shafts with a diameter of 1.8 m and a total length of 1000 m were sunk. The horseshoe-shaped cross-section is 30 m², in the area of ​​the crossing station 66 m². Relay rooms for signaling technology are also located in the tunnel.

Tunnel 4 was the longest railway tunnel in Africa when it opened, but had to surrender this record to the 14.2 km long Gautrain tunnel that was broken through in September 2009 and leads from Johannesburg Park Station to the portal near Marlboro .

tourism

With the opening of the new route, the original route over the pass was taken out of service and its overhead line dismantled. However, a large part of the route between Matroosberg and Osplaas has been preserved and is used by a tourist train, which consists of a farm tractor converted into a two-way vehicle and two summer wagons , which runs under the name Hexpas Express .

literature

• Tim Hart: Cultural historical assessment of the Hex Passrailway, Worcester to De Doorns . Ed .: University of Cape Town. June 1998 ( sahra.org.za PDF).

Web links

Commons : Hex River Tunnel  - collection of pictures, videos and audio files

Commons : old route over the Hex River Pass  - collection of pictures, videos and audio files

Individual evidence

1. ^ David Tennant: The Railway System of South Africa . In: Royal Commonwealth Society (Ed.): Proceedings of the Royal Colonial Institute . 1898, p. 3–30 ( Internet Archive [accessed March 27, 2016]).
2. ^ John Bond: John Molteno: Founder of the South African Railways . Ed .: SABC . August 14, 1954, p. 3 .
3. ↑ ^{a b c d e f g h i j k l} South African Construction World . July 1990, p. 60-61 .
4. ↑ ^{a b c d e f} South African Panorama . October 1989, p. 25 .
5. ^ Jose Burman: Early railways at the Cape . Human & Rousseau, 1984, ISBN 0-7981-1760-5 ( Google Book [accessed March 27, 2016]).
6. ^ ^{A b c} Charles Lewis, Les Pivnic: Soul of A Railway. In: System 1, Part 3: Wellington to Touws River. Pp. 31–32 , accessed April 21, 2016 . 
7. ^ Cape Government Railways (ed.): Report for year ending December 31, 1909 . Section VIII: Dates of Opening and the Length of the different Sections in the Cape Colony, from the Year 1873 to 31st December, 1909.
8. ^ ^{A b c} Historical Background of the Hex River Railway. In: Hexpas Ecotrek. Archived from the original on March 12, 2012 ; accessed on March 27, 2016 (English). 
9. ^ Reader's Digest Association South Africa, South Africa Directorate of Surveys and Mapping: Reader's Digest Atlas of Southern Africa . Reader's Digest Association South Africa, 1984, ISBN 0-947008-02-0 ( Google Book [accessed March 27, 2016]).
10. ^ Leith Paxton, David E. Bourne: Locomotives of the South African Railways: A Concise Guide . C. Struik, 1985, ISBN 0-86977-211-2 ( Google Book [accessed March 27, 2016]).
11. ^ South African Construction World . May 1990, p. 55 (diagram).
12. ^ Compagnie Interafricaine de Travaux v South African Transport Services and Others (680/89). South Africa: Supreme Court of Appeal, accessed March 27, 2016 . 
13. ^ South African Construction World. October 1990, p. 59.
14. ^ ^{A b} The Civil Engineering Contractor . February 1986, p. 35 (diagram).
15. ^ ^{A b} The World's longest Railway Tunnels. The World's longest Tunnel Page, November 15, 2013, accessed March 27, 2016 . 
16. ↑ Hexpas Express. In: Hexpas Ecotrek. Archived from the original on March 12, 2012 ; accessed on March 27, 2016 (English). 

 Map with all coordinates: OSM | WikiMap