Messages for Semaphore Signals

Messages for Semaphore Signals

Fully-Integrated Semaphore Signals

Semaphore messages are not independent of the technology of the signal: fully-integrated semaphore messages differ from those of less integrated forms. It is appropriate therefore to examine the message configurations separately.

There are variant forms of the fully integrated signal but the Anglo-American pattern predominates (NS constitutes a major variant). U.K.-U.S. semaphores though not identical share many similarities and can be regarded as an unit; significant differences will be noted. Perhaps one-fourth of railway systems in this study use this model of the semaphore.

An examination of the Anglo-American signal can be a dialectic process of thesis and antithesis: signals are upper quadrant (UQ) or lower quadrant (LQ); signals are left-handed or right-handed (for this study these characteristics can be abbreviated as UQRH or UQLH, and LQLH or LQRH). Message positions are horizontal and 45 degrees for both UQ and LQ; UQ has also vertical position. Signals are square-ended, pointed, fish tail (or swallow-tail, U.K.), or round-end. Signals are true rectangles or tapered; signals are red or yellow (chevrons and other secondary symbols and colors are subsumed within the dominant shape and color). Signals may be home or distant, manual, semi-automatic or automatic (there are also nuanced distinctions: outer home, intermediate home,etc); there are also specialized functions: shunting signals, calling-on signals, repeating signals, etc.

The quadrants define the core messages. A halt message is horizontal whether UQ or LQ; a horizontal indication denotes cease movement without regard to the type of signalling. This indication occupies the mid-point of the signal apparatus (see Chapter 29B for illustrations). Caution indications are at a 45 degree angle whether UQ or LQ. Proceed indications are not the same for UQ and LQ. For UQ proceed is a vertical indication while for LQ the indication is about 45 degrees (LQ usuallly requires two arms so angle of blades is not contradictory, (GRS 1913, SP) .

For most systems there is agreement on the significance of blade shapes. Square-end blades designates a home signal while fishtail (or swallow-tail) indicates a distant signal. Pointed blades announce automatic signals. In some systems (for example, ANR 1947, 112, 118) square-end signals indicate absolute signals and pointed-end blades indicates permissive signals. NSW offers a variation that is apparently contrary to other usages: square-end blades designate three-position UQLH signals but fish-tailed blades are used with two-position UQLH (NSW 1952). Color patterns for semaphores are uniform: red blades with white stripes or bands for home signals, and yellow blades with black chevrons or red blades with white chevrons for distant signals.

Night messages for home signals are red and green for two-position, and red, green, yellow for three-positions. Variations based on nineteenth century practice, can be found with distant signals: red and green instead of yellow and green; in these instances red has a cautionary meaning. The message of caution is simple and easily understood for many systems but becomes complex in others especially in URO and North American systems.

The Anglo-American pattern may dominate integrated semaphores but other models exist including those of Italy (FS 1983), and the Netherlands (NS 1978, 30, 34, 40). Spain bears a partial resemblance to the Anglo-American form (RENFE 1978, 1-10). Italy employs a double semaphore ("Accoppiati") unique to that system. Two blades are mounted in tandem though each is capable of free movement. The signal produces messages of caution and of proceed though with qualifications. The Spanish semaphore has the shape, color and markings of U.S. and U.K. practices but the lamp and lens unit is separate from the blade. Blades are red with white secondary markings with some pointed and others square-ended; pointed-ends have chevrons while the square ended models have bands.

The semaphores or seinpaals of the Netherlands are visually at variance with the Anglo-American model but are nonetheless an integrated signal (Op de Rails 1985a) . Home signals are marked by a round oval (similar to the Germanic model), distant signals have an square end; junction signals have an arrow-shaft end (Alkmaar); shunting signals are also marked by an arrow-shaft end with a secondary marking of a white stripe near the outer end. Dutch influence was at work in pre-U.K. South Africa, and also in Indonesia; that influence is clearly present in the latter system (PKNA 1971) .

Partially and Non-integrated Semaphore Signals

Integrated semaphores have much in common even though they are found in many widely-separated systems. European semaphores (formsignals) are marked by more diversity than Anglo-American versions though Europe is a much more restricted area. Similarities as well as dissimilarities can, however, be summarized. Points of commonality include a signal form of signal in many systems (home and distant distinctions are frequently not present or if present then created through a joint usage of semaphores and signal boards), heavy presence of German-originated signals, and an overlap of signal shapes within sub-regions.

Sweden and Finland employ a single form of semaphore signals which are UQLH; three-positions require two arms (SJ 1979, 21; VR 1984). Both systems employ a hollowed out blade for the viewing of the halt aspect and this can be regarded as a partially integrated signal. Signal aspects are different for the two systems; for example, Sweden employs two green G for 40 km/h aspects and Finland G/Y for 35 km/h messages. The blades have red and yellow horizontal stripes for Sweden and red and white stripes in Finland; both include an oval at the end of the blade (SJ 1979, 21; VR 1984) .

The Germanic form is UQRH and is used for home or main indications (for this paragraph see DB 1981, 18; see also DR, PKP, CFR, etc.). The signal is rectangular with an oval end; arms are white and bordered in red. Two arms are required for three positions. Vertical and red marks halt, 45 degrees with two arms and G/Y lamps denotes caution, and one vertical arm with G indicates proceed. Lamps and blades are fully separated.

The USSR code book does not include semaphores (SZD 1979), but the 1984 German railway yearbook (EJ 1984, 152) lists semaphores for the USSR including an unusual three-arm signal. It denotes entrance to a station and indicates that the train crew is to be prepared to stop.

Czechoslovakian semaphores resemble those of Hungary and Yugoslavia except that both ends of the blade are squared-off. The color pattern is red and white. The signals of all three nations have separate lamps and blades but without the disc end common to many central European systems. Hungary and Yugoslavia both have a half-sphere end to the blade. JZ and CSD blades are red with a center white stripe; this is also true of MAV. CZD also includes some blades with a yellow center stripe (see signal codes of JZ, MAV and signal information of AZDP; see also ER 1984).

CZD indicates halt with horizontal indication and red light; 45 degree position and green light of course denote proceed.

"Proceed with caution" marked by a double arm of which one is red and white and the other yellow and white, and a yellow lamp. An additional speed, "caution, allowed speed 40 km/h" requires both arms and two yellow lamps. A lattice work semaphore is also included in CZD (see AZDP and EJB), and a double-arm lattice work semaphore is employed by SBB (SBB 1982, 65). The propeller arm has simple messages of proceed, stop and qualified proceed (DB 1981, 50-51).

Yugoslavia has three formsignal aspects which include the basic proceed and halt indications and a modified proceed signal marked by G/Y lamps (JZ, 27). Hungary has green and red aspects but no yellow. A double green aspects denotes (MAV, 2 64). URO formsignals are in the Germanic tradition and have standard aspects. Two arms at 45 degrees and lamps indicate a proceed to branch line message; the same indication with G/Y lamps is a variant of that (URO 1962) . Belgium semaphores combine European and UK-US schools of signalling. Home signals consist of rectangular red blades with white stripes and square ends; the distant signal is yellow with an arrow-shaft shaped-end with black chevron. These signals emit standard messages (SNCB 1980).