Skip Ribbon Commands
Skip to main content
Skip Navigation LinksEskom Heritage>Museum Artifacts Part 3
Museum Artifacts Part 3

Museum Artifacts Part 1​  ​    Museum Artifacts Part 2​​        All Museum Photos​


A PORTABLE MILLIVOLTMETER 

Manufactured by Siemens and Halske, Germany. It is believed it was built circa 1900.
It is a portable, moving coil type that was used with external 60 millivolt shunts.
5 amp shunt multiply the reading by 0,1
20 amp shunt multiply the reading by 0,4
60 amp shunt multiply the reading by 1,0
Approximate overall dimensions 200 mm x 100 mm x 220 mm

The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.​

A PHASE ANGLE METER

Manufactured in the USA by Weston Electrical Instrument Corporation, Newark, New Jersey.

The instrument measures the angle between the current and the voltage in an AC circuit when these quantities are represented by vectors.

TECHNICAL DESCRIPTION
Scaled 0 - 90° 180 - 90° 180 - 270° 360 - 270°
Max. Voltage 260/130/75/17,5V Rated Voltage 220/110/65/15
Max. Current 6/3A Rated Current 2,5/1,25A Frequency 50Hz
Range selection by selector switch.​

Voltage selection by terminal. Current selection by terminal and link.
Model 480
It is a portable instrument in a wooden case with cover and leather carrying handle.
Approximate overall dimensions 220 mm x 280 mm x 210 mm
One terminal top is missing.
The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.​

A FLAME-PROOF MINE TELEPHONE 

Manufactured by Siemens Brothers and Company Limited, London. Circa 1946. This type of telephone was used in fiery mines and industrial situations with high ambient noise levels.

This particular phone is mounted on a wooden baseboard with an inscribed plaque. The inscription reads "Presented to Mr. H P Alexander as a memento of his association with Colenso Power Station." Mr. Alexander was ESCOM’s Regional Manager in Natal.

Approximate overall dimensions 320 mm x 190 mm x 610 mm
The telephone is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.​

A CONDUCTIVITY METER 

​Made by Evershed and Vignoles, London.

Circa 1935. This instrument was supplied by British Agencies Limited, Johannesburg.

The conductivity meter is essentially a resistance-measuring device arranged to display the reciprocal of the resistance i.e. the conductivity. It has a moving coil movement without control springs but with two moving coils so connected that their resultant torques are in opposition. The one coil carries the current (I), or a definite portion of the current, flowing through the test piece. The other, a current proportional to the voltage applied (V). The displacement of the movement at balance is proportional to the ratio of the two torques i.e. V/I which, by Ohm's Law, is proportional to the resistance or inversely proportional to the conductivity.

A hand driven generator built into the instrument case provides power.

The instrument is a portable type used to measure the conductivity of earthing systems, electrolytes, etc.
Scaled 0 – 3000 Ranges 0 - 3000/300/30 Patented 1907
The instrument is housed in a wooden case with levelling screws.
Approximate overall dimensions 200 mm x 340 mm x 220 mm
The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.​

A PORTABLE AC/DC VOLTMETER 

Believed to have been manufactured by Hartmann and Braun, Germany in 1897.

It is believed that this instrument was first used by the General Electric Power Co., Ltd., Germiston and was later taken over by the Victoria Falls and Transvaal Power Co., Ltd. (VFP).

It is a portable moving iron type for measuring voltage in AC or DC circuits.

Scaled 0 – 200V
It is housed in a wooden case with a lockable front flap and brass-carrying handle.
Approximate overall dimension 220 mm x 110 mm x 215 mm
The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.​

WHEATSTONE BRIDGE

A PORTABLE WHE​ATSTONE BRIDGE made by H. Tinsley and Co., London. Circa 1940.

This is a portable, laboratory type used for the measurement of medium range resistance.
Ratio arms (by plug setting) 10, 100 or 1000 ohms
Reference standard (4 decades) 0 - 11'110 ohms in steps of 1ohm
The instrument has both Battery and Galvanometer keys, each with provision for locking in the "on" position.
Contained in a Teak case without lid.
Approximate overall dimensions 395 mm x 215 mm x 150 mm

N.B. This portable version of the Wheatstone Bridge was, at one time, commonly known as a "Post Office Box"

The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.​

AN ASTATIC ELECTRODYNAMOMETER​ 

Believed to have been made by Siemens and Halske, Germany in 1887.

Approximate overall dimensions 100 mm diameter x 150 mm

The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.​

A UNIVERSAL GALVANOMETER 

Made by Siemens and Halske, Germany in 1897.

Siemens and Halske supplied this instrument to the Rand Central Electric Works (RCEW) after the construction of Brakpan Power Station in 1897.

Approximate overall dimensions 200 mm diameter x 100 mm

The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.​

A WHEATSTONE BRIDGE

A WHEATST​ONE BRIDGE made by Siemens and Halske, Germany in 1887. 

Approximate overall dimensions 100 mm diameter x 150 mm

The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.

AC GALVANOMETER​

AN AC GALVANOMETER made in the United Kingdom by H. Tinsley and Company. Circa 1925.

This instrument is a sensitive vibration type 432. It is approximately 150mm in diameter and measures 300mm high. Serial number 13385

The instrument is currently on display at Palmiet Power Station

TURBINE CONDENSER VACUUM GAUGE

Turbine condenser vacuum gauge made by Tycos in USA or Canada.

Scaled 0 – 10 inches, and 0 – 5 pounds.

Mounted on a base with approximate overall dimensions 140mm wide x 750mm high.

The instrument is currently on display at Palmiet Power Station.

PRINTING DEMAND METER

Printing demand meter (maximum demand printometer) manufactured in USA by General Electric. Circa 1950.

Type PD-5. Serial number 626103. Operating voltage 18V DC.

Enclosed in a cast-iron case with approximate overall dimensions 300mm wide x 330 high x 205mm deep.

The instrument is currently on display at Palmiet Power Station.

TIME LAG RELAY

An electromechanical constant definite time delay relay made in the United Kingdom by Reyrolle.

Time delay is fixed at 5 seconds. Operating voltage is 15V DC.

Type T.D. Article number 415C98. Serial number BQTTD67.

Enclosed in a cast-iron case with approximate overall dimensions 240mm wide x 180 high x 110mm deep.

The instrument is currently on display at Palmiet Power Station.

SINGLE ELEMENT INSTANTANEOUS RELAY

A single pole, attracted armature, non-directional, instantaneous over current relay. Manufacturer was possibly the Victoria Falls and Transvaal Power Company Limited or Escom.

Enclosed in a cast-iron case with approximate overall dimensions 230mm diameter x 100mm deep.

The instrument is currently on display at Palmiet Power Station.

THREE ELEMENT INSTANTANEOUS RELAY

A three pole, balanced beam, non-directional, instantaneous over current relay. Manufacturer was possibly the Victoria Falls and Transvaal Power Company Limited or Escom.

Type instantaneous over current. Serial number 8995. Setting range 2 – 10A 50Hz. Trip circuit 24V DC.

Enclosed in a cast-iron case with approximate overall dimensions 370mm x 200mm high x 110msm deep.

The instrument is currently on display at Palmiet Power Station

THEODOLITE

A "Rand Model" theodolite used in the United Kingdom by Cooke Troughton and Simms specially for use in the mining industry. Circa 1925.  It was manufactured to a 1913 patent, and was used by the Victoria Falls and Transvaal Power Company Limited from 1925 to 1940.

The instrument is currently on display at Palmiet Power Station.

TALLY CHAIN

A survey tally chain used by surveyors at the beginning of the twentieth century to measure surface areas.

It is 100 Cape feet (103,3 imperial feet) in length.

The instrument is currently on display at Palmiet Power Station.

TIME LAG RELAY 

An electromechanical definite time delay relay, made in the United Kingdom by Metropolitan Vickers. Circa 1950.

Type AKA. Serial number 788073.

Time delay range 0 – 5 seconds. Operating voltage 110V DC. Hand reset flag indicator.

Enclosed in a cast-iron case with approximate overall dimensions 185mm x 220mm high x 120mm deep.

The instrument is currently on display at Palmiet Power Station.

UNIVERSAL POTENTIOMETER 

A potentiometer is used to measure alternating and direct current. It was made in the United Kingdom by H. Tinsley and Company. Circa 1930.

Serial number 1278.

Approximate overall dimensions 850mm long x 420mm wide x 90mm high.

The instrument is currently on display at Palmiet Power Station.

PROPORTIONAL DIVIDERS

An instrument used by draughtspersons for enlarging or reducing the length of lines without use of scales for measurement. Circa 1950. This was used extensively for indicating cadastral boundaries on aerial photographs for the purpose of route planning.

The length of both legs of this particular instrument is 180mm.

The instrument is currently on display at Palmiet Power Station.

PLANIMETER

The planimeter is an instrument used for calculating the area of irregular figures. Circa 1940.

This instrument was used by the Victoria Falls and Transvaal Power Company Limited Company Limited (VFP).

The approximate length of both legs of the instrument is 380mm.

The instrument is currently on display at Palmiet Power Station.

PANTOGRAPH

The pantograph is a precision instrument used for the reduction or enlargements of maps. Circa 1940.

It is based on a parallelogram joined at all four corners, and secured at the prolongation of one side. It was used extensively in drawing offices in the early years of the twentieth century. It has been replaced by photographic methods.

The two long sides of this instrument measure approximately 620mm. The two shorter sides measure approximately 300mm.

The instrument is currently on display at Palmiet Power Station.

CURRENT TRANSFORMER

A dry type switchboard current transformer made in the United kingdom by Switchgear and Equipment Company Limited.

Reference number W.O. 88T/1. Ratio 15/5. 50Hz. 15VA maximum. Class C. Maximum voltage 11 000V.

Approximate overall dimensions 150mm wide x 200mm high x 100mm deep.

The instrument is currently on display at Palmiet Power Station.

CURRENT TRANSFORMER

A through type portable current transformer manufactured in the United Kingdom by Ferranti Company Limited.

Reference number 219095. Ratio 800/5. 50Hz. 7,5VA. Class AL. Tested at 2000V.

It is labelled "VF & TP Co. Ltd. Test Dept."

Enclosed in a wooden case with approximate overall dimensions 200mm wide x 200mm high x 140mm deep.

The instrument is currently on display at Palmiet Power Station.

CURRENT TRANSFORMER​

A through type portable current transformer manufactured in the United Kingdom by English Electric Company Limited.

Reference number PPS 29645. Ratio 500/5. 26 - 100Hz. 15VA. Maximum voltage 6600V.

Approximate overall dimensions 320mm wide x 130mm high.

The instrument is currently on display at Palmiet Power Station.


​​