The Hukong Valley Route (1942)

The Hukong Valley route for an Indo-Burma railway. Sadiya Frontier Tract, ch. 4, pp. 255-7 "History of the frontier areas bordering on Assam: 1883 - 1941" by Sir Robert Reid. Printed at the Assam Government Press, Shillong, 1942

Made available by the Internet Archive.
Source: B R Ambedkar / IIT Hyderabad Edited by R Sivaramakrishnan. Posted to IRFCA on: January 8, 2008.

Railway route connection between Assam and Burma from Ledo

The Hukong Valley route for a railway connection between Assam and Burma from Ledo to Sahmaw was surveyed by Mr. F. W. Allum, C.B.E., Engineer-in-Chief in 1920 and 1921. His report is dated the 30th April 1922, and the following extracts give the main facts.

3. Early in the nineties of the last century the desire for a railway connection between India and Burma was so strong that the Government of India appointed Mr R. A. Way, a very experienced and capable Engineer, to investigate the problem, and he examined three routes in this order:

(1) From Chittagong on the Assam-Bengal Railway along the Arakan coast and over the An Pass to the Chindwin river in Burma; the coast route.

(2) From the neighbourhood of Lumding on the Assam-Bengal Railway, by way of Manipur, into tho Kubaw valley at Taromu, and thence, crossing the Chindwin river near Yuwa, to a junction with the Mu Valley Railway in Burma near Wuntho ; the Manipur route

(3) From Ledo on the Dibrugarh-Sadiya Railway in the north- east corner of Assam, via the Hukong Valley, to a junction with the Mu Valley Railway in the neighbourhood of Mogaung ; the Hukoig Valley route.


6. In the cold weather of 1895-96 he reconnoitred the third route and estimated its length at 284 miles and the cost at 383 lakhs of rupees."


9. In the winter of 1917-18 Mr Stevenson, Executive Engineer of the Assam-Bengal Railway, explored the Patkai ridge for a distance of 20 miles west of Way's pass and 25 miles east thereof and discovered the lowest point on the ridge within this distance, the Sympana Saddle. He established the impracticability of any route west of Way's pass and east of the Sympana Saddle.

10. Early in 1919 the Government of India decided to make a preliminary survey of the Hukong Valley Route


24. The Hill Section dividing the Assam plains from the Hukong Valley, of which the principal feature is the Patkai range, the watershed between Assam and Burma. In the viciniiy of the route the range varies in altitude from 6,800 at the Maium Bum to 3,080 at the Sympana Saddle, where the railway will cross it. Extensive spurs nearly as high as the main range are thrown off in directions indicated by the main rivers, roughly, after a quick turn, parallel to the main range arid these spurs throw off subsidiary spurs to right and left, forming a tangled mass of hills through which the main rivers, the Namchik and the Namphuk on the Assam side of the watershed and the Loglai and Turong on the Burma side, present the only practicable route for a railway: the hill sides, especially in the upper portions of the main ridge, are very steep and crimped to an extraordinary extent, like the teeth of a bevil Wheel and the soil consists of sandstone or shale covered with a shallow layer of earth in which clay predominates supporting an exuberant growth of tree and bamboo jungle

25. A part of the hill section, from the crossing of the Namphuk to the summit of the Patkai range, lies in the Sadiya Frontier Tract, and the remainder is not under British rule.


43. The length of line, as surveyed, from Ledo in Assam to Sahmaw in Burma is 278.71 miles, of which 17 miles are in the Lakhimpur Frontier Tract, 46 miles in the Sadiya Frontier Tract, both under the Assam Government, 151 miles in unadministered territory (from the Patkai range to the eastern boundary of the Hukong Valley), and 64.71 miles in the Myitkyina district of Burma. The route I recommend, see paragraph 173, will be about 268.36 miles in length."


70. The proposed route via the Namphuk Valley. The extreme costliness of a railway over the Patkais compelled us to look for the shortest practicable route over these mountains and from the Assam plains to Digum Jup this appear to be the line I have shown in dotted red on the map, i.e. , Ningrangnong to Nambong Jup on a ruling grade of 0.7 per cent, and Nambong Jup to Digum Jup via the Sympma tunnel ...

The cost was estimated (paragraph 173 of Allum's report) at Rs.6,98,66,000.

The potentialities of the Nongyong Lake as a source of power in connection with what was known as the "Hukong Valley Project" were investigated in the course of the Hydro- Electric Survey of India. The report of Mr. B. A. Blenkinsop, officer in charge of the Hydro- Electric Surveys, Assam, dated 1923,* states that "the Hukong Valley power station should form an excellent commercial undertaking". Mr. Blenkinsop's succeeding remarks are interesting in view of the long-drawn controversy, as yet unsettled, regarding the Assam-Burma boundary, in this area. He observes " though situated in the Naga country 40 miles from Namchik, the finished products turned out by the Electro-Chemical factories in connection with this power station would practically be at the present rail head of the Assam-Bengal Railway, for the rough estimate of cost provides for constructing a line from Ledo to the Power House site of the scheme at the foot of the Patkai Range. I understand that the boundary between Assam and Burmah has not yet been finally decided on. If the present territorial boundary as at present shown on the older maps, some 20 miles to the south-east of the Patkai Range, beadopted, then the whole of this project lies in Assam, but if for geographical reasons the Patkai Range is taken as the dividing line, then the Power House and pressure pipe line would be in Assam, while the reservoir would be in Burma. 'This project, it will be realized, is of intense importance to Assam, for if taken up commercially, it would certainly be a big, if not the decisive factor in the construction of the Indo-Burma connection railway along this route and consequently all that this railway would mean to the further prosperity of Assam.

* Report on Hydro-Electric Surveys, Assam, 1923.


Sir Robert Neil Reid (1883-1964) was Governor of Assam from 1937 to 1942.

To visualize the route, the following sheets of AMS series of topographic maps may be used:

Dibrugarh sheet:

Ledo is at 27N18, 95E44

Putao sheet:

Maium Bum is at 27N12, 96E02; Loglai Hka (river) is to its E and joins Tarung Hka S of Karang Bum at 27N08, 98E08

Maingkwan sheet:


Sahmaw Jn is located at 25N14, 96E48 to the WSW of Myitkyina, the two town being connected by a railway

The original source material used on this page is believed to be out of copyright, and/or these extracts are believed to be fall within the scope of fair use under copyright law. Material selection and editing by R Sivaramakrishnan, 2008.