Tuesday 20 August 2013

Travelling on the Qinghai - Tibet Railway

On 11th July 2013, I boarded a train at Xining West in China to travel to Lhasa (arriving the next day). I've already described the first part of the journey in a post here and the final part of the journey (the following day) here. In this post, I'll add information of a more technical nature. All my pictures taken on the journey are in the set QingHai - Tibet Railway.

The train I travelled on was the K917 which had left Lanzhou, 228 km east of Xining, at 12:08.

The timetable for this train is given below. We also made brief stops at a few stations not shown in the timetable.

Station Distance* Arrive Depart
Xining West - 14:44 15:04
Delingha 509 20:49 20:55
Golmud 818 00:19 00:39
Anduo 1512 08:39 08:41
Naqu 1638 09:59 10:05
Dangxiong 1796 11:54 11:56
Lhasa 1960 14:35 -

* Distance (in km) from Xining West.

Summary

Putting aside political considerations, it must be said that the railway to Tibet is a remarkable engineering achievement. To construct a railway in such an inhospitable area required great determination. The electrified section from Xining to Golmud was completed in 1984 (and it's double-track as far as Tempung) but the single-track non-electrified extension from Golmud to Lhasa was only finished in 2006. Almost half the length of line between Golmud and Lhasa is laid on Permafrost. In general, the line speed limit is 120 km/hr (75 m.p.h.) but this is reduced to 100 km/hr on the permafrost sections. The railway appears well-engineered and fairly carefully executed.

At Tanggula, the railway is at the highest elevation of any railway in the world at a little over 5,000 metres. In fact, 80% of the line from Golmud to Lhasa is above 4,000 metres, significantly reducing oxygen levels and, for this reason, the passenger coaches are fully sealed and oxygen is carried. There's an interesting (if frightening) article about altitude sickness here.

The route required a number of tunnels and Fenghuoshan Tunnel (1,338 metres long) at an elevation of 4,905 metres is the highest railway tunnel in the world.

The People's Republic of China and the Soviet Union co-operated quite closely following World War II, so it's unsurprising that the railways in China show many similarities with Russia's railways, which I had an opportunity of studying during my trip on the 'Golden Eagle' private train (described here).

At the end of this post, there are some sites linked which give a little more information about railways in China and Tibet. Tibetan place names along the railway are now generally rendered in Chinese characters. When these characters are converted into English letters, a variety of spellings can result so I'm still rather confused about the identity of some of the places I passed through.

Electric Locomotives

I wasn't able to go onto the platform at Xining West until the train had already arrived and I didn't have an opportunity to confirm the motive power before we departed. After about three hours, when our route executed sharp curves, I finally could see that, as anticipated, we had electric haulage by one of the modern 'Harmony' HX-series Co-Co 25kV a.c. locomotives. These locomotives are either imported or built in China under technology transfer agreements. The other trains we passed were hauled by similar 'Harmony' locomotives or the earlier 'Shaoshan' SS-series locomotives.

The 'Harmony' HX-series electric locomotivewhich hauled my train to Golmud.

There's more information about electric locomotives in China here.

Diesel-Electric Locomotives

Chinese-built

There's more information about diesel-electric locomotives built in China here.

Co-Co diesel-electric locomotive shunting at Xining West.

Co-Co diesel-electric locomotive DF_1309 near Lhasa.

Imported NJ2

The NJ2 diesel-electric locomotives used on the Golmud-Lhasa section were built by GE-Transportation in the United State, as their type C38AChe. The 78 units have running numbers NJ2 0001 to NJ2 0078. A driving cab is provided at one end only and the units are intended to operate as 38 2-section locomotives.

An NJ2 unit weighs-in at 136 tons so, even using a Co-Co layout with two six-wheel trucks, axle loading is 23-tons. Since GE locomotives normally use four wheel trucks, the bogies for the NJ2 locomotives were made by United Gonivan in New South Wales, using a well-established design with a fabricated (rather than cast) frame.

The engine is a variant of the successful four-stroke turbo-charged 7FDL16 diesel engine (arranged 8+8 cylinder V-formation) as used in the GE 'DASH' series. The engine brochure gives a maximum engine power of 3355 kW although other sources quote 3,800 kW for the NJ2 power plant. Of course, reduction of air supply at high altitude affects diesels (as well as people) - high-output diesel engines depend on the turbo-charger even at low altitudes to provide sufficient combustion air.

A scale model of a single NJ2 unit on display in Shanghai Railway Museum.

On arrival at Lhasa, I walked to the front of the train hoping to get a picture of our motive power but the twin-unit was already uncoupled and moving off down the headshunt.

The pair of NJ2 locomotives which hauled my train to Lhasa.

Civil Engineering Works

Even with the benefit of modern machinery, the constructional problems must have been daunting. Embankments, cuttings, bridges and tunnels were required, together with stations and other buildings required by the railway. Later in my trip, I saw something of the work in progress building the new railway from Lhasa to Shigatse, which is presenting similar problems. This gave me a better insight into the building of the line I travelled on to Lhasa.

The railway is fenced. On the Xining - Golmud section, this was generally a series of concrete posts with metal sections fixed between each pair of posts. Each metal section comprised a rectangular frame of welded tubes supporting a panel of steel mesh. The whole metal section was then painted green. In the mountain section, I saw some simpler post and wire fencing. Beyond Golmud, instead of the metal sections, a pre-cast concrete panel, also mesh-covered, is used.

Metal section fencing near Lake Qinghai.

Beyond Golmud, instead of the metal sections, a pre-cast concrete panel, also mesh-covered, is used.

Concrete section fencing beyond Golmud.

Overhead 25 kV a.c. Electrification

On 'plain line', pre-cast concrete masts are commonly used.

Reinforced Concrete Masts supporting the Overhead Line.

In the vicinity of stations and where there are additional running lines, steel portal structures of various designs are used. Some have rectangular fabricated masts and rectangular trusses but there are also types with tubular masts and triangular trusses.

Portal Structure featuring tubular mast and triangular truss.

Traction substations are conventional in appearance and appear to take in power from the National Grid.

Traction Substation

Permanent Way

Flat-bottom rail, pre-cast concrete sleepers and modern rail fixings are set in deep ballast giving an excellent ride. Continuous Welded Rail is generally used on 'plain line' (certainly Xining West to Tempung) and 6-hole fishplates on jointed track. Turnouts are of substantial construction and cast crossings are employed with heavy-duty check rails.



Concrete sleepers, flat-bottom rail, modern rail fixings and 6-hole fishplates (Xining West).

Cast Crossing and Heavy-duty Check Rails (approaches to Lhasa).

Distance and Gradient Markers

These markers are pre-cast tablets. Distance markers show distance in kilometres from Xining West. Intermediate 100 metre markers are also seen. Gradient markers are also tablets, with an arrow to indicate 'Up' or 'Down' and a figure which I believe represents 'rise or fall per thousand'. There are pictures showing the Kilometre Markers for kilometres 226 and 227 in the section below on signalling equipment.

Signalling Equipment

I was impressed (as I was in Russia) at the neatness of the layout of the signalling equipment. Electric point machines (of a very compact design) are used for point operation. Track circuits appear to be generally used for train detection. Running and shunting signals are all colour light. A standardised rectangular signalling equipment room is widely used (often to be seen at each end of a station near the points and signals controlling entry to a number of passing loops). I believe some form of Centralised Traffic Control is in use, possibly based in Xining.

In the section above on 'Overhead 25 kV a.c. Electrification', there is a picture showing a 3-aspect ground signal (apparently with a smaller subsidiary aspect below) and a high-level signal comprising two 2-aspect signal heads with a subsidiary aspect below.

Signalling equipment at east end of Niao Dao, showing colour light ground signals, housings for signalling and track circuit equipment and insulated rail joints. Kilometre Marker '226' is also visible.

Signalling equipment at west end of Niao Dao, showing point machine, housings for track circuit equipment and insulated rail joint. Kilometre Marker '227' visible on right. Marker with red lettering on left (possibly a cable marker).

Picture showing two high-level signals. The red-roofed building is a standard signalling equipment room. Traction Sub-station on the right.

The railways of 25 countries are members of OSShD - the Organisation for the Combined Operations of Railways. This seeks to standardise practices in member countries and affects about one third of the railway route mileage in the world. Since Russia, China (and Vietnam) are members, similar methods of signalling are used in each of these countries.

References

Rail transport in China (Wikipedia).
List of railway lines in China (Wikipedia).
Qinghai–Tibet Railway (Wikipedia).
List of stations on Qinghai–Tibet Railway (Wikipedia).
Lhasa–Shigatse Railway (Wikipedia).
China Railways Map.
China Tibet Train (with map).
China Train Guide (Travel agency).

Locomotives in China

List of locomotives in China (Wikipedia).
Chinese diesel locomotives (Railways of China).
Chinese electric locomotives (Railways of China).

Railway Signalling in China

Signals at China Rail (Hans Schaefer).
Chinese Railway Signals (refers to Hans Schaefer site).
OSShD Signals.