Baltimore and Ohio Railroad
Color-Position Light Signals

CPL lamp unit Color-position light signal lamp unit.  Ever wonder what the inside of one of these looks like?  Well, thanks to CG Tower's great CPL pages - which include catalouges from signal manufacturers - we can take a look under the hood (pun intended) of a GRS CPL lamp unit.  The diagrams and list of parts on this page were taken from General Railway Signal's 1937 catalog, Part H, on CG Tower's site.

CPL signal parts 4
CPL signal parts 2
CPL signal parts 3
CPL signal parts 3
CPL signal parts 1

Note: In drawings 2 and 4, the red areas indicate the background, or target, of the signal.

Part no.
Description
1
Screw, no. 10-32 x 3/16" fil. hd. for fastening ring (27) to bezel ring (20)
2
Spring for stud (11)
3
Screw, no. 10-32 X 3/4"fil. hd. for fastening hood (22) to bezel ring (20)
4
Bushing for screw (9)
5
Bushing for screw (9)
6
Nut, no. 14-24 x 1/8", hex head, for terminal posts
7
Nut, no. 14-24 x 5/16", hex head, for terminal posts
8
Washer, for terminal posts
9
Screw, no. 14-24 x 2-7/16", sq. hd., used for terminal posts
10
Adjusting nut, for light unit
11
Stud, for adjusting light unit
12
Plate, for closing opening in bottom of light unit
13
Screw, no. 8-32 x 3/8" fil. hd., for fastening plate 912) to light unit
14
Screw, no. 6-32 x3/16", for fastening sighting strip (32) to shield (16)
15
Cover, complete, includes clip and chain, for light unit
16
Shield, for light unit
17
Stud, 3/8"-16, for fastening light unit to background
18
Nut, 3/8"-16 x 3/8" hex, for stud (17)
19
Spring for stud (17)
20
Bezel ring for light unit
21
Screw, no. 6-32 x 5/16", with clip, for fastening lens (25) to light unit
22
Hood, for light unit
23
Incandescent bulb, 13.5 volt, 17 watts, for light unit
24
Lens, outer doublet hot spot, 8-3/8", 4" focus
25
Lens, inner doublet, 5-1/2" dia. green, for light unit
25a
As above, except yellow
25b
As above, except red
25c
As above, except lunar white
25d
As above, except clear, frosted
26
Gasket, for lenses (24 and 31)
27
Bezel ring, as shown, for light unit
28
Pin, 3/32" x 3/4", for locking stud (17) to bezel ring
29
Screw, no. 6-32 x 11/32" hex hd. with washer, for fastening sighting plate (33) to light unit
30
Roundel complete, includes roundel clip and spring assembled together, for light units figs. B to B4 onlyB
31
Lens, outer doublet 30° spredlite 8-3/8" dia., for light units figs. B to B4 only
32
Sighting strip, for light unit
33
Adjustable sighting plate, for sighting light units
34
Bracket, for lamp receptacle
35
Screw, no. 14-24 x 1-3/8" sq. hd., for clamping bracket (34) to stud (11)
36
Receptacle, only, for lamp receptacle
37
Plunger, for lamp receptacle
38
Spring, for plunger (37)
39
Block, for receptacle
40
Adjusting nut, for receptacle

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Last updated Sunday, December 28, 2008