[Excerpts from] 

The Western Union Telegraph Company

 Inside Plant Catalog


 Apparatus, Material and Tools

July 1, 1929

[Transcription courtesy of Richard S. Loveland, N3IA]

[Note:  Information shown in RED was not part of the original text, and is included to provide additional information and links to photos.]

To provide for quicker downloads I have broken this document into smaller segments.  All items are in alphabetical order, so you can click the appropriate link to view the appropriate area.

A-C      D-O       P-R     S-Z


ARM, RESONATOR EXTENSION. A metal arm for converting type 3-A to type 7-A resonator; so constructed that it can be placed between the arms of a 3-A resonator to lengthen it. L-10", Ht (over all)--2-3/4", W--1-1/4"
BASE, KOB, 1-B.*  [See also wood base below]

Used for mounting key and main line sounder to make KOB set. Intended for permanent use. Piece of 3/8" ebony asbestos with two cross cleats of Bakelite to act as feet. Drilled for 2--#6-32 x 1-1/8" R.H.I.M.S. for sounder, 3--#6-32 x 3/4" F.H.I.M.S. for key and 2--#8 x 1" R.H.I.W.S. for fastening to shelf, screw and nuts being furnished with base. L--8-3/4", W--4-11/16", Ht--5/8"

*1-A base was piece of asbestos without cleats, wood screws being used to fasten instruments.

BASE, KOB, WOOD. Used for KOB service when sets are to be disassembled within a short time. Piece of 3/8" wood same size as 1-B base. Screws to be ordered separately as follows: 2--#8 x 7/8" R.H.I. wood for sounder, 3--#6-32 x " F.H. Br. wood for key, and 2--#8 x 3/4" R.H.I. wood to fasten base down (if needed).
BATTERY, DRY. See Cell, Dry.
Battery, Gravity

gravbat.jpg (30524 bytes)

For use where it is impractical to establish power plants or use main line sounders. See also Caustic Soda Battery. A 6" (dia) x 8" glass jar with zinc electrode (crowfoot zinc) hung near the top, and copper electrode (battery copper) in bottom surrounded by blue vitriol (copper sulphate or "bluestone"). The cell action forms zinc and copper sulfate solutions which remain practically separate because the latter is much heavier, hence the term "Gravity" battery. Battery oil is used to prevent evaporation. Open circuit voltage 1.07 volts. Internal resistance 2 to 4 ohms. Capacity 200 A. H. per lb. of zinc, 87 A. H. per lb. of blue vitriol. Maximum continuous current: 150 mils for main line service; 250 mils for local line service. An average main line cell will use per year: 8 lbs. vitriol, 2 zincs, 1 copper. An average local line cell will use per year; 10 lbs. vitriol, 2-1/2 zincs, 1 copper. 


List of parts:  Jar, Gravity Battery Vitriol, Blue
  Copper; Battery  Oil,  Battery
  Zinc, Crowfoot  
BLUESTONE. See Vitriol, blue.
BLOCK, CONNECTING, 7-B.  block7-b.jpg (32754 bytes) Used as a connecting point between flexible wires of arm resonators; registers and the wiring of the associated equipment; also on various telegraph sets. See also 73-A. Composition base with three pairs of screw posts for three individual circuits. Has hinged metal cover to protect screw posts. L--2 1/8", W--1". Ht--7/8".

Used to fasten sounder to resonator hood. A #8 32" x 1-1/2" R.H.I. machine screw with thumb nut and washer, all nickeled.

BOX, CALL, 6-B*0645.jpg (78986 bytes)callbx8b.jpg (47677 bytes)

Used on messenger call circuits to send coded signal. A clockwork mechanism mounted on an oval porcelain base, enclosed by metal cover through which operating handle projects. Rotation of handle winds up mechanism so will open and close call circuit through code wheel and contacts when handle is released. Binding posts are concealed by cover but have exposed lugs to afford quick testing. Code wheels must be ordered separately. L--5-7/8", W--3-5/8", Ht (over handle)--3".

* Type 4-B (Specn. E-63) is much similar (but has exposed binding posts) and is used interchangeably. Type 6-A is much the same as 6-B but does not have test lugs. Type 5-A (Specn. 577) now obsolete, was designed to fit standard single gang flush wall switch box.

BOX, JACK, 1-A.   Used only for maintenance of bridge testing sets already so equipped. Switch controlled sets (Spec. 1937-A) do not require. Wooden box, hard rubber front, holding 5 jacks WE 156 and 2 resistances, wired to external binding posts. Plug and cord included. W--8-3/4", D--7", ht--3-1/2".
Used as a terminal and cross connect box in unit swbd. installations in which such facilities have proven necessary.
Box same size as a double unit switchboard in which are mounted five small blocks with a total of 20 terminal lugs.
Door of box has compartment for storing protector fuses and blocks.  Ht--6  W--8,  D--6.
BRACE, KEY, 1-A. Used on Morse operating positions to prevent sending machine ("bug") from sliding into Morse key. Piece of #18 ga. brass angle 3-1/2" long, base ", upright leg 5/8".
CELL, DRY. Used for open circuit work on telephone and telegraph circuits. Standard #6 dry cell with Fahnestock clips. Max voltage 1.5. Dia. 1-1/2", H--6"

chair1a.JPG (14520 bytes)

Used by Morse and automatic (except simplex) operators, also by others who do not require standard wood office chair. Steel framework with composition seat and back rest. Back feet are of swivel type to prevent damage to floor if chair is tipped back.  Seat--17" front, 16" depth; Ht of seat--approx. 18"; Ht (overall)--32-1/2".

*There are a number of older types of chairs in use and care must be exercised when ordering repair parts to see that they are of the proper type. See Specn. 1818-B on repairs. 

  Older types of chairs were furnished with solid feet. These should be changed to swivel (back feet only) whenever composition floor is laid or when other maintenance work is being done.


For use in small offices where a large clock is unnecessary or undesirable. 

Flat watch case type of clock, case 1" x 1 " set on a small bracket for wall or shelf mounting. 8-day rim wind, rim set.

* Older type has 2" deep nickel plated round case. No code number was assigned.


Used in offices which have no time service connections.  Commercial type 8-day pendulum clock,12" dial. Arabic numerals octagonal case about dial. Ht--32", W--18".

* Type 2-B had round case about dial. Older types which had no code number had Roman numerals.

CLOCK, SELF WINDING.  [Order on Form 1810-A]

0905A.jpg (114138 bytes)

Used in Western Union and subscribers offices where time service connections are available. See standard time service pamphlets for various types.

Special 1-C clock, with or without synchronizing electromagnet, is used to operate dry cell 10 volt time stamps in offices where power operated stamps cannot be provided as outlined in Spec. 194-G. This clock has time stamp contacts for direct connection of stamp and has space in case for batteries. Case is rectangular--28" x 18" x 8". 

Standard clocks can be equipped with time stamp contacts (closed 1 sec. per minute on the half minute), battery control contacts (closed 5 secs. before and after the hour and motor generator control (closed 20 secs. before and 10 secs. after the hour). 

Special time stamp contacts which close every ten seconds can also be secured. Clocks may be ordered equipped with contacts, or if a clock is available the movement can be ordered to have contacts added.

Western Union used a variety of self winding clocks.  Follow the link for a sampler.


gravbat.jpg (30524 bytes)

Used for lower element in gravity batteries. 

Three 2" x 6" leaves of #32 ga. copper riveted together at a central point and a 15" stem of #14 ga. insulated copper wire attached to one leaf. Leaves are laid flat together for shipment but are opened up like spokes of a wheel when used.


Used for testing and patching on double conductor switchboards. 

Tinsel copper conductors each covered with a floss and braid, and the whole covered with an outer colored braid, max. dia. about 5/16". Cords 511-B and 536-B are single and double conductor test cords respec. Cords 525-A and 526-A are double conductor patch cords, the first having plugs wired tip to tip and sleeve to sleeve, and the second having the connections reversed. Cord 527-A has three ends and made in a "Y" shape with all plugs in series. Length is clear distance between plugs.

Code No. Length Number Plugs Outer Color Specn.
511-B   6'     1   1-C White 2503-A
525-A 4",1',2',3',5'     2   3-B  Green  1302-A
 526-A 4",1',3',5'     2    3-B  Red  1303-A
527-A 1', 3'     3   3-B Green 1304-A
536-B 2'. 4'. 6"+      1   3-B Green 2504-A

* Cords of W.E. manufacture with same code number were formerly furnished.

Spade tips of cords WE 511 will not fit screws on 7-B connecting blocks.

+ Semi special--do not order unless called for in specns.


Used to tie single conductor idler plugs to jack boxes. Piece of gray cotton sleeving 12" long.

*Dummy plug attachment 1-A was formerly used.

CORD, DOUBLE CONDUCTOR [Test and Patching]  See cords 525, 526, 527 and 536.
CORD, LAMP, TWISTED PAIR, .... GA., NEC.  [Also specify finish and color] [Feet] Used in some lighting fixtures and for misc. test purposes. Standard twisted pair cord, available in sizes #8 to #18 incl.
CORD, PRINTER, BLACK.  [Form 2968] Used to connect up line side of simplex printer on 32 type table. 

Piece of #18 ga. reinforced type P-1/64 lamp cord with one end equipped with a 3-B plug. Outer color is black to differentiate it from transmitter cord which is red.

CORD, RESONATOR.   [Pieces or Feet] Used with arm resonators to connect up sounder. 

Standard twisted pair lamp cord. 

If desired for resonators, order by pieces in which case lengths five feet long with ends whipped and soldered will be furnished. Order by feet for other special use.

CORD, SENDING MACHINE.wedge.jpg (48437 bytes) Used on semi-automatic sending machines ("bugs") Double conductor cord about 24" long and 1/4" dia. with cord tips at one end and special wedge plug at other to fit under circuit closing lip of Morse key.
CORD, SINGLE CONDUCTOR. [For swbd, test sets]  See Cord 511-A.

Used in making patches on single conductor switchboards. Stranded copper wire (equivalent to #14 ga.) covered with rubber to overall dia. of 1/4". A plug #1 type is attached to each end. Furnished in 1', 2', 3', 4', and 6' lengths. (Clear distance between plug shells.)

* 5-A cord, Specn. 768-A, was designed for same service but had outer black braid.

CORD, SWITCH, .... CONDUCTOR, WITH WEDGE. Used as test cord on spring jack switchboards, also on old style table jacks for master sets. 

Copper tinsel conductor, either SINGLE or DOUBLE, rubber and cotton insulated and laid into a round conductor with an outer black braid. (Older purchases have had blue or green braid.) One end has flat wedge plug and other has a piece of #14 ga. wire soldered to end of conductor. 

Furnished in 6' length only.

CORD, TRANSMITTER, RED.   Used to connect up transmitter side of simplex printer on 32 type table. 

Piece of #18 ga. reinforced lamp cord Type P-1/64, with one end equipped with one end equipped with a 3-B plug. Outer color is red to distinguish it from printer cord which is black.



cuttr.jpg (18413 bytes)

Used on tape printer positions to cut off tape when gumming it down.  A round thimble-shaped piece of nickel silver set on a flat polished plate, the edge of which is used as the cutter.  Furnished in sizes #5 to 12 inclusive, thimbles being of different diameters and lengths.  Plate 3/4" x 1 1/2", Ht overall -- 1".

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