BANGKOK ELECTRICAL SUPPLY
Reprint of The Far Eastern Review, May 1931
One, of the great power developments in the Far East is found in Bangkok, the capital of Siam, where the Siam Electricity Company, Ltd., holds a virtual monopoly for furnishing light and power to the city and its suburbs.
The history of this development goes back to May, 1887, when a concession was granted by the Siamese government to Messrs. John Loftus and A. du Plesis de Richelieu to operate a horse drawn tramway from Bangkolem (the southern-most point of the town) to the royal palace. The concession was transferred to an English e company (the Bangkok Tramway's Company, Ltd.) which worked it fur some years with but poor results. This company went into liquidation and on May 23, 1892, transferred the concession to a Danish company.
This company electrified the line (which work was completed in May, 1894, at a time ,when most cities in Europe were without electric tramways) and operated it for some years until in November, 19U0, the concern was taken over by the Electricity Co.. Ltd.
Independently of these developments Messrs. L. de Richelieu and Aage Westenholz obtained in July, 1900, another concession to construct and operate a tramway (the Samsen Tramway) which connected the northern part of Bangkok with the center of the town and this concession was also transferred to the Siam Electricity Co., Ltd., and traffic was commenced on this line in September, 1901.
Electric lighting was first started in Bangkok by a Siamese nobleman in 1890 and was taken over by the government in 1893. It was transferred to an American company, the Bangkok Electric Light Syndicate, in 1897 and this company obtained a contract for lighting of public roads and government premises which contract after certain alterations was taken over by The Siam Electricity Co., Ltd., upon its formation.
The Siam Electricity Co., .Ltd.-This company was formed and incorporated in Copenhagen on December 27, 1898, for the purpose of acquiring the concessions, contracts and rights of the former companies and started its existence with a registered capital of £33,400.
In the course of 1900 and 1901 the fusion was completed whereby all the electric tramway and light undertakings in Bangkok were combined under the S. E. C.
One of the first undertakings of the new company was the removal of the machinery of the two old tramway stations to the electric light station situated in the temple premises of Vat Lieb which latter station the company had acquired by virtue of its concession and where the company's activities arc still carried on.
In the course of time the prosperity of the company grew and ill 1907 it acquired a controlling interest in the Siam Tramway Company Ltd. A company started under Royal Charter in 1904 by Siamese Princes and nobleman to operate another system of tramways in Bangkok.
The Siamese Tramway Co.'s power station was demolished and its management taken over by the S. E. C. and while the two companies each maintain their independent character, the share-holders and. board of directors are to a great extent the same and the management is common for both companies, while the current is supplied from the power station of the S. E. C.
S. E. C. Power Station.
The S. E. C. Power Station is situated in the Vat Lieb compound and a Klong connects the power station with the river (Menam). This connection is of great importance, as it provides the only channel through which all fuel is transported. The following is a short description of how the power station operates from the time the fuel enters in the Klong, until the current leaves the station for the different purposes in the town.
The main fuel used by, the S. E. C, is paddy husk transported to the power station in boats each containing about 400 baskets (between 9 and 10 tons).
Besides this; liquid fuel is kept in storage in case of shortage of paddy husk, and shortly two boilers will be erected provided. with chains grates stoker for coal burning.
Boats are discharged by means of a Suction plant, capable of discharging two boats in 45 minutes into the husk shed which has maximum capacity of 450 tons.
From the shed, husk is transported to the Babcock & Wilcox boilers by means of four screw conveyors. The boilers are equipped with grates the upper portions of which are fixed fire bars, whereas the lower parts are movable, enabling the fuel to slide automatically over the grate. From. the lower part of the grate the ashes drop into a water-drain discharging into the river.
The boilers are erected in two rows, one row consisting of four boilers and the other two. The maximum capacity of the boiler-room is 10 boilers. Each boiler is capable of producing 12,500 kg. of steam per hour at a pressure of 14 kg. per cm 2.
They are provided with economizers and superheats to increase the economy of the steam plant. The feed pump plant for the boilers consists of three Weir turbine pumps the capacity of each being 35,000 kg. per hour at a pressure of 15 kg. from the boilers the steam enters into the engine hall and goes to the turbines through the main steam pipes.
The engine hall is provided with six turbines of a total capacity of 16.500 kilowatt hours. The individual capacities of the turbines are as follows: 2 by 5,000 slat; 2 by `5,000 stal, 2 by 1,250 kilowatt. hours A. E. G.
Each turbine drives an alternator which generates current at a tension of 3,600 volts and 50 cycles. From the alternator the current is distributed by means of a switchboard through the different feeders. From these feeders current is supplied all over the town. the generating plant of the tramways and to the auxiliary service of the power station.
The water necessary, for condensing the exhaust steam from the turbine is pumped up to the power station by means of a pump plant situated on the river, the capacity of which is 6,000 cubic meters per hour. The discharge of this cooling water goes back to the river through the ash drain or through the power station Klong. The windings of the alternators are also cooled by air passing through air filters of the viscous oil system.
The tramway current is generated by three electric motor generators (Construction Electriques de Belgique), capacity of each being 800 Kilowatts. Each high tension synchronized. motor of the group drives a dynamo which supplies the direct current of 550 volts to the feeders of the different lines through a special switchboard.
The development of the tramway has made it necessary to erect one substation at Bangkok Dock to supply current to the southern part of the tramway lines, just as a substation in Bang Na converts the alternating current into direct current for the Paknam. Railway Co.
As already mentioned.
Two kinds of current are generated at the power station.
(1) three phase alternating current, 50 cycles, 3,600 volts for light and power purposes.
(2) direct current, 550 volts, for tramway traction.
The current generated at the power station is brought into the town by means of high tension underground cables.
The cables supplying alternating current are connected to three high tension switch cabins, situated at different places in the town and thence the supply is transmitted by means of high tension overhead lines to which are connected the transformers which transform the tension from 3,600/100 volts for light purpose and 3,600/3 by 175 volts for power.
There are at present 12 high tension distributing feeders of which one. feeder is especially used, for public street lights, one feeder for Government customers, and 11) feeders for general
distribution of light and power.
Practically all the high tension distributing feeders call be
inter-connected either at the high tension switch cabins or by means of overhead line switches.
One high tension feeder is used to supply current to the Bang Na substation 12 km. from the Capital where A. C. E. C. cascade converters transform the current from 3,)o volts A.C. to 550 volts D.C. and supply current to the Paknam Railway Co., Ltd., which connects Bangkok and Paknam, a distance of about 21 km.
The high tension line which supplies current to the above substation is also carried through up to Paknam and supplies current to this small town.
The tramway distributing feeders which are 10 in number also leave the power station in underground cables and extend to various places in the town deemed most suitable as points of connection with the tramway sections.
Practically all the tramway sections are supplied with current generated at the power station. with the exception. however, of three sections in the southern part of the town which receive current from the Bangkok Dock substation where two converters of 360 kw. (C.. E. B.) generate the necessary D.C. supply.