Your browser is unsupported and may have security vulnerabilities! Upgrade to a newer browser to experience this site in all it's glory.
Skip to main content

22nd May 2020

This post is all about Morse code, which can seem complicated but was actually a really important way of communicating, right up until the end of the 20th century.

Dah dah dah dit – is anyone there?

This post is all about Morse code, which can seem complicated but was actually a really important way of communicating, right up until the end of the 20th century.

Like in flag semaphore, Morse code encodes each of the letters of the alphabet and the numbers 0-9 with a unique code. The code is made up of a sequence of dots (AKA “dits”) and dashes (AKA “dahs”). The dot duration is the basic unit of time measurement in Morse code messages.

International Morse Code (Wikimedia Commons)

Once operators have learnt the corresponding code for each letter or number, Morse code can be transmitted over long or short distances by on-off keying any sort of information carrying medium, such as torch light, sound, or electric current.

Most often, Morse code is sent as clicks or long and short pulses. This means that people are able to learn Morse code by sound, rather than by reading it.

Some people are able to memorise Morse code and translate messages in their heads, and transmit messages at a rate of 40 words per minute!

On top of just learning the letters and numbers in Morse code, operators had to know the various shorthand ‘prosigns’ of Morse. For example, QRS meant ‘speak slower’, and HH AR meant ‘disregard this transmission; out’. And you thought learning the letters was hard enough!

Morse code is named for Samuel Morse, the inventor of the telegraph. Morse’s early telegraph signal allowed pulses of electric current to be transmitted from one receiver to another. And so, Morse code was developed as a standard way of knowing what the electrical pulses meant.

This telegraph machine in the Hull Museums collection was used to transmit Morse Code messages from the degaussing station at Alexandra Dock, Hull. It belonged to Arthur Beckett James, the officer in charge of the station.

Telegraph Key (Hull Museums)

Messages were typed out here using the black plastic lever key. When the lever is pressed down, the signal is on, and when it is released, the signal is off.

Radiotelegraphy using Morse Code became important at sea at the beginning of the 1900's. It became a way of sending long range messages, that could be easily encrypted if the messages had to be secure.

Did you know? After the sinking of the Titanic, the importance of ships and coastal stations listening to a common frequency for radio distress calls was realised.

RMS Titanic (Hull Museums)

This video tour of the Arctic Corsair includes former Skipper Jim Williams giving a tour of the Wireless Room (from 18:43), where even in the 1960s, a telegraph machine for using Morse code was part of the kit used to communicate between ships.

You might have heard of the Marconi Wireless Telegraphy Company – founded by Italian inventor Guglielmo Marconi in 1897. Following the campaign of the Headscarf Revolutionaries in Hull in 1968, having a telegraph operator on board trawlers became mandatory. The telegraph operators were paid directly by the Marconi company, not from the profits of the trawler. The telegraph operators would have been experts at Morse code, which they would have used to transmit emergency signals when necessary.

Even with advances in technology, Morse code was used as an international standard for maritime distress until 1999, when it was replaced by the Global Maritime Distress and Safety System.

Some of today’s volunteers on the Arctic Corsair also used Morse code to signal using light

All ships carried a signal lamp. Here is the Aldis lamp that we have on the Arctic Corsair

Aldis Lamp (Hull Museums)

It has the alphabet written on the inside of the storage box. This was useful as it would be the crew not the telegraph operator using the lamp. Anyone with experience of Morse code found themselves in demand as a former skipper Ron recalls: “There was a deckhand who had been a signals man in the forces, we called him Soldier Bill who would often communicate on behalf of the Skipper using the Aldis Lamp.”

Signalling with light was quick and easy and the powerful light of an Aldis lamp could be seen for miles.

Len, also a skipper told us: “Up until the late 1960's when anchoring at Killingholme, communication was always with Aldis, you would be given a landing number and then fly the appropriate number pennant.”

Using light to signal was also more private as Morse code radio messages could be heard by rival ships looking for the best fishing grounds.

When fishing was good both Ron and Len used Aldis lamps to communicate with nearby company ships and away from the main fleet!

Today you can download Morse code apps for mobile phones and signal using the light. Why not have a go yourself!