chapter  14
4 Loran-C ground equipment
Pages 1

Master and secondary transmitting stations are

located at strategic places to provide the required

geometry for obtaining navigation information.

Transmitter towers are typically 700-1300 feet

high and radiate between 400 and 1600 W of

power. The master and secondary stations are

formed in groups known as chains as discussed

earlier. Baseline distances vary from chain to

chain since many stations are located on islands

to provide oceanic coverage; distances of between

175 and 1000 nm are typical. The majority of

these chains are in the USA and Canada; other

chains are located in Russia, the northern Pacific,

Europe, Asia and the Middle East. The master

stations are identified as ‘M’ and the secondary

stations are identified from the series ‘W, X, Y

and Z’. The US Coast Guard (USCG) provides

full details of each chain, together with an on-line

handbook containing very useful data and

information relating to Loran; details can be

found on their website The

USCG introduced Loran-C into Europe, the

system was transferred to the host nations in

Table 14.1 provides a list of currently available

Loran-C chains, together with a summary of how

many secondary stations are associated with the

master. Table 14.2 provides details for the

Northwest Pacific chain; this comprises stations

on the Japanese mainland and a number of islands

in the Pacific. Figure 14.7 gives an illustration of

the area of coverage for this chain.