CLP’s Hok Un Power Station – immediately post World War Two

IDJ: When Hong Kong was liberated after the surrender of the Japanese, one of the first groups to arrive was “Shield Force.”  This mainly comprised 3,000 Royal Air Force personnel who had been diverted from their expected task of building Pacific island aerodromes to assist the Allied advance towards Japan.

Not all RAF personnel in the war were involved in flying aircraft, there was a very large engineering backup, including the little known Airfield Construction Service. After the British military had gained control of Hong Kong there was a great need to restore services and utilities such as electricity. A group from the RAF contingent were assigned to China Light & Power’s Hok Un Power Station and successfully managed to restore basic electricity supplies.

The Airfield Construction Service published a series of bulletins they called ‘magazines’ describing the activities of their Service in various parts of the world. An edition relating to restoring electricity in Kowloon has been transcribed and is offered below. [see below the images]

The China Light & Power company history glosses over the RAF’s and Royal Navy’s essential contribution to restoring electricity production, but does have descriptions on the state of the power station and electricity distribution systems at that time.

A chapter on Shield Force and its involvement in the liberation and restoration of services in Hong Kong is published in Chapter 22 of the book ‘The Royal Air Force Airfield Construction Service 1939-1946’ by Anthony Betts-published in 1995

A website for the Airfield Construction Service now exists, only one Hong Kong item is displayed at the moment:-http://www.rafacb.org.uk/page64.html

The following images of the China Light and Power’s (CLP) Hok Un Power Station, are all from October 1945. Click to enlarge.

IDJ added in an email sent in August 2018: The Hok Un pics I acquired about 20 years ago from the Secretary of the Airfield Construction Unit Association who was living in Kent at the time. I was interested in what he had, if anything, on the short-lived Ping Shan Airport project that the construction unit was involved in preparing during 1945-46 in Hong Kong.

He also showed me the Hok Un power station material, and as I had worked for CLP and was based there for a while, he gave me copies of it.

Nothing was revealed to me about the photographs origins. I assumed they had been donated to the Association by a member. Not sure if the Association still exists, although I believe they may have a presence somewhere on the Flikr internet site where I have seen Ping Shan airfield construction pictures.

Click on the image to enlarge.

CLP 1 Hok Un Power Station

Electricity distribution control room

CLP 3 October 1945-just after Japanese surrender-No 1 steam turbine-Ron Smith reblading turbine

No 1 steam turbine – Ron Smith reblading the turbine

CLP 4 October 1945-just after Japanese surrender-No 5&6 steam turbine generators

No 5&6 steam turbine generators

CLP 5 -October 1945-just after Japanese surrender-Steam boiler No12-note size of visitors on gallery

Steam boiler No.12 – note size of visitors on the gallery

Visitors on boiler chain-grate that feeds in coal

Visitors on boiler chain-grate that feeds in coal

Repair group + Chinese helpers outside the power station building

Repair group + Chinese helpers outside the power station building

RAF No.53 RU(P) repair group - farewell Chinese dinner

RAF No.53 RU(P) repair group – farewell Chinese dinner

The farewell Chinese dinner menu

The farewell Chinese dinner menu

farewell Chinese dinner - participants

The farewell Chinese dinner – participants

 

No.5358 Wing (Airfield) Construction pose for a photograph

No.5358 Wing (Airfield) Construction pose for a photograph

 

AIRFIELD CONSTRUCTION SERVICE  TECHNICAL MAGAZINE
Vol.2. No 2 dated MAY 1946

OVERHAUL OF KOWLOON POWER STATION
By Squadron Leader E.M. Jackson, Royal Air Force

A great deal of work has been carried out by tradesmen of No. 53 R.U.(P) and No. 5715 M & E Construction Flight on plant in the Kowloon Power Station, Hong Kong.

The plant had suffered considerably during the Japanese occupation due to neglect and removal of machines etc., in addition all the fuel conveyors were out of commission and the mechanical and electrical conditions of the boilers and alternator sets was exceedingly bad.

The general plant in the station is as follows:—

Turbo—generator Sets
No.           K.V.               K.W.          FREQ.
1 &  2      6.6              6.000           50
3 & 4      2.2                   750           60
5              2.2              3.000           60
6              6.6              5.000           50

Pedestal bearing
7          6.6             12.500           50—— destroyed beyond local repair

Frequency Changers
No.        K.V.             K.V.A.         FREQ.
1 & 2      2.2              1.800          50/60

AUX. D.C. Battery Charger
3.         25 K.V. Sets.o

Turbo Generators 3, 4, and 5 and the frequency changers feed into a separate board located in the Turbine Room which acts as a sub-station for the 60 cycle circuit. This supply is required by the dockyard and can be fed either way through the rotary frequency changers.

The turbine room is divided into two parts, the North end containing gen­erator sets 1 to 6, and the South end generator set 7 with additional sets in the process of erection.

Boiler House North

Boiler        Output      lbs/sq.in.
No.         lb/hr            pressure          Superheat
1              50.000             200                 600*F
2              75.000             200                 600*F
3 to 6                              Removed
7 to 10  10.000              200                600*F

Boiler House South

11         100,000              450                 780*F
12         200.000              450                 750*F

Operated at 200 lb/sq.in. and 600 F

Coal and Ash Conveyors

Personnel of No. 53 R~U.(P) and No. 5715 M & E Flight took over the maintenance of this plant on the 6th September, 1945, when the continuity of the town supply was most uncertain. The R.A.F. tradesmen filled such posts as Electrical and Mechanical Superintendents, Shift Engineers, Turbine Room Attendants, and Draughtsman.

In the initial stages 3 Officers and 15 0.Rs were employed on this work, in addition to 291 Chinese civilian tradesmen, these numbers are being gradually reduced.

Slowly but surely important overhauls were effected — the boilers were being fired by wood fuel fed into the grates by a human chain of Chinese coolies and owing to the difficulties encountered in obtaining both coal and wood fuel, the Station Engineer decided to convert No.1 boiler from coal firing to oil burning which proved to be most satisfactory.

The modifications carried out have resulted in the installation of two oil tanks with a capacity of 17 tons each on the roof, which act as settling tanks, each being fitted with a bleed valve to draw off any water. The consumption of the burners with the boiler on full load is approximately 34 tons per 24 hours and an equalising valve has been fitted between the tanks which can be used in an emergency. Filters have been provided at the outlet together with a pressure gauge indicating the head of oil in the tank.

The burner works on the flit gun principle, a jet of steam passing over an oil orifice at 65 lb/sq.in. creating a 5 inch vacuum on the burning tip, the object being to atomise the oil and thereby ensure complete combustion. The normal oil pressure on each burner is from 4 to 5 lb/sq.in.

The fuel line consists of a 4 inch diameter pipe fed from the oil header tank through twin filters. Each burner has a master valve and control valve. In addition there is a drain pipe at the end of the fuel line for draining off oil and/or preventing air locks.

On starting up, the steam is taken from No.1 boiler superheater but is changed over to No.2 boiler when a pressure of 160 lbs/sq.in. has been reached. Two gauges indicating the pressure of the steam and oil supplied to the burner are fitted in front of the fuel burner control valves, and a steam trap is fitted at the end of the steam range to drain off water forming through condensation. Six burners are utilised on full load.

Pre—heated primary air is admitted at the rear of the burner and is given a rotary motion (by passing over shaped baffles), each burner being separately controlled whilst the ash pit dampers act as master dampers to the primary air supply.

Secondary air is admitted on the underside of the fire grate, the object being to keep the grate cool; it then passes through the front wall, completing combustion and at the same time keeping the front wall cool.

To light the burners, a block of wood covered with sacking is soaked in oil, placed in front of No.1 burner and ignited. The others can be lit from No. 1 without any difficulty.

Other major work included the complete overhaul of No’s l, 5 and 6 turbo-generator sets, In the case of No.1 it was found necessary to re-blade the last stage wheel of the turbine followed by dynamic rebalancing. To effect the latter, a dynamic balancing machine capable of taking any spindle up to ten tons was designed and installed.

A complete overhaul was made of No’s 1, 2, 7, 8, 9, and 10 boilers, includ­ing feed pumps and other auxiliaries. Electrical maintenance and repairs were also made whilst this work was proceeding.

A considerable number of components were manufactured in the power house workshops (for which machinery was requisitioned) and included 50 wheel barrows (for carrying coal), 3,000 cotter pins, 60 coal conveyor buckets, oil fuel injectors for No.2 boiler and ducting extensions, whilst several castings were made in the R.U.(P) workshops.

The fact that the auxiliaries for these generator sets was rated to run at two different frequencies (i.e. some were 50 cycle, others 60 cycle) caused a certain amount of trouble when efforts were being made to restore the supply after a complete shut down, but this was soon overcome after a little practice.

The China Light and Power Company, the owners of this station, have been much impressed by the work which has been carried out under the direction of the R.A.F. staff, and they hope soon to be able to relieve the R.A.F. entirely on these supervisory duties when their own engineers arrive on site, the major work included the complete overhaul of No l,5 and 6 turbo generator sets, In the case of No.1 it was found necessary to re-blade the last stage wheel of the turbine followed by dynamic rebalancing. To effect the latter a dynamic balancing machine capable of taking any spindle up to ten tons was designed and installed.

A complete overhaul was made of No’s 1, 2, 7, 8, 9, and 10 boilers, includ­ing feed pumps and other auxiliaries. Electrical maintenance and repairs were also made whilst this work was proceeding.

A considerable number of components were manufactured in the power house workshops (for which machinery was requisitioned) and included 50 wheel-barrows (for carrying coal), 3,000 cotter pins, 60 coal conveyor buckets, oil fuel injectors for No.2 boiler and ducting extensions, whilst several castings were made in the R.U.(P) workshops.

The fact that the auxiliaries for these generator sets was rated to run at two different frequencies (i.e. some were 50 cycle, others 60 cycle) caused a certain amount of trouble when efforts were being made to restore the supply after a complete shut down, but this was soon overcome after a little practice.

The China Light and Power Company, the owners of this station, have been much impressed by the work which has been carried out under the direction of the Royal Air Force staff, and they hope soon to be able to relieve the R.A.F. entirely on these supervisory duties when their own engineers arrive on site.

See:

  1. ‘Power-The Story of China Light’ by Nigel Cameron, Hong Kong Oxford University Press-1982

This article was first posted on 23rd January 2014.

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One comment

  • Leanne Molloy

    Please may you contact me. I have a news paper article from back then. Honoring people who helped restore the power to the station. My grandfather was one of them. His name was Aster Molloy.

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