Titanic revisited

The Titanic, Revisited

Many of the experts on the loss of the Titanic blame the radio operators for the delayed

response to its plight. To some extent, the experts are right.

Being able to communicate using radios was a novelty in 1912, the year Titanic took its

first and final voyage. The first-class passengers were happy to pay the 12 shillings 6

pence cost to send 10 words to their family, friends, and business associates from the

North Atlantic.

The radio itself was a spark-gap transmitter which could operate 1.5 to 5 kilowatts on

either 1 MHz (300 meters) or on 500 kHz (600 meters). It had a range of about 400

miles during daylight, and about 1000 miles at night.

What seems like common sense to us today, hadn’t occurred to the powers-that-be in

1912. They had no concept of priority or emergency traffic. So the “Having wonderful

time X Wish you were here” messages from the passengers were the first in line to be

handled. It turns out that Marconigrams were a very lucrative business.

The antenna the Titanic had was a series of horizontal parallel wires (known as a T-type

wire antenna) which were mounted on masts on each end of the ship. Marconi himself

designed the antenna which was about 600 feet long and stood nearly 200 feet above

the deck. I’m told that, unless the transmitter was set on the specific frequency the

antenna was resonant at, most of the rf was radiated through the feedline. (By the way,

the picture is a reasonable facsimile of what the Titanic’s radio schematic probably was

like.)

In case you were wondering, that 12 shilling 6 pence for ten words cost for a

Marconigram in 1912 translates to about $100 - $115 today. No wonder the Marconi

Company pushed the radio operators to keep the passenger message service as the

priority.

(Note: Thanks to David Ham, N6SIK, for getting me to think about the Titanic this week.

It’s a fascinating subject.)