The older steam whistles were almost always actuated with a pull cord (or sometimes a lever) that permitted proportional (tracker) action, so that some form of "expression" could be put into the sound. Many locomotive operators would have their own style of blowing the whistle, and it was often apparent who was operating the locomotive by the sound. Modern locomotives often make use of a pushbutton switch, which takes away the fine control over the way the whistle is sounded.
Because trains generally have extremely high mass and relatively low braking friction, they are inherently difficult to stop at normal speeds. Since train whistles were extremely inexpensive to institute compared to other more effective warning devices, the use of loud and distinct train whistles had become the preferred safety fallback for railroad operators.
John Holliday describes the history of train whistles as originating in 1832, by way of a stationmaster at the Leicester and Swannington Railway opening, that the trains should have an audible signaling device. A local musical instrument builder was commissioned to provide a steam-powered whistle, then known as a "steam trumpet".
The article also describes a train-bus collision arising from a train that used truck horns instead of the standard whistle. Although the bus driver heard the horn, he thought it was a truck rather than a train.
American steam locomotive whistles are legendary for their different sounds. They came in many forms, from tiny little single-note shriekers (Called Banshees on the old PRR) to larger plain whistles with deeper tones (a famous deep, plain train whistle is the "hooter" of the Norfolk & Western, used on their A and Y class Mallets). Even more well known were the wonderful multi-chime train whistles. Nathan of New York copied and improved Casey Jones's boiler-tube chime whistle by casting the six chambers into a single bell, with open "steps" on top to save on casting. This incredible whistle is still considered the "King of train whistles", and it's musical chord is wonderful to hear! This whistle is the most copied train whistle in the USA, and many railroad's shops cast their own version of it, the old Southern Pacific having one of the finest copies. Another very popular American train whistle, was again, a Nathan product. This was a five-note whistle, with much shorter bell, and therefore, much higher in pitch. This whistle sang a bright G-major 6th chord (GBDEG) and again, was heavily imitated, copies being made by many different railroads. Even the Chinese copied American five-chime whistles for their own locomotives. The final most popular American chime train whistle was the three-note version. These were either commercially made (Crosby, Lunkenheimer, Star Brass, Hancock Inspirator CO. among others) or shop-made by the railroads, themselves. Some famous and very melodious shop-made train whistles were Pennsy's passenger chimes and the old B&O's step-top three chimes. But the most beloved of all three-chime train whistles to the public and railroaders alike were the deep-chorded "steamboat minor" long-bell's. A well know commerially made chime was Hancock Inspirator Company's three note step top. These found use on almost every American railroad, and their deep, melodic sound is legend. Some railroads copied these also, examples being found on the old Frisco and Illinois Central. Perhaps the most famous of the three-chime train whistles were those home-made ones on the old Southern Railway. These were all distinctive as having top-mounted levers. They had sweet sounding short-bell three-chimes as well as their (highly copied) long-bell three-chimes of passenger engine fame, especially their PS4 engines, one of which resides today in the Smithsonian Institution. Two-note and four-note train whistles never caught on with North American railroads with one exception: Canadian National Railway created a large four-chime step top whistle for limited use on some of their locomotives. These were not common and only a few survive today in the hands of collectors. Otherwise American train whistles were in single-note, three-note, five-note and six-note combinations.
A few very well known American railroads, famous for their whistles: Southern Pacific for their wonderful six-chimes. Union Pacific for their Hancock "steamboat" chimes. Reading Railroad for their unusual high-pitched passenger six-chimes. CB&Q RR for their melodious five-chimes, and very unusual three-chimes. B&O RR for their wonderful three-chime steptops and very different sounding six-chimes. Grand Trunk for their pretty shop-made six-chimes (Nathan copies). New York Central for their wonderful shop-made six-chimes.
In the UK, it is normal for diesel and electric multiple-units and locomotives to have two horns, of different pitches (rather like two-tone emergency road vehicles - police cars, etc). This has given rise to drivers "playing" unofficial combinations of low and high notes. When passing through the local station in the Yorkshire town of Ilkley, drivers soon began to play the first line of the folk song, On Ilkla Moor Baht 'at on their loco/DMU horns, using a series of short blasts: LOW, high - high - high, LOW, high - until those on high had low thoughts "abaht" the practice, and banned it.
The first four notes of Beethoven's Fifth Symphony - played during World War II as the Morse code 'V' (for Victory) – can be sounded on a loco horn as three short notes and a longer one, often the last note on the lower-tone horn.
Early railways had the communication chain or cord from the carriages connected to a "brake whistle" on the engine. This was usually of a lower note than the normal whistle used by the driver. Right up to the demise of England's Great Western Railway, on 31 December 1947, its engines still carried two whistles.
Some Great Western "autocoaches" - from where the driver operated the steam engine's regulator and brakes, when the engine was propelling one or more autocoaches - still had a whistle connection with the engine's brake whistle, although a gong (much like a tram gong) was fitted at the front of each autocoach and was operated by the driver using a foot treadle.
Back in the days of steam, when assisting engines pushed long goods trains up steep gradients (or "banks"), the train would come to a halt at the bottom of the bank. The assisting engine - or "banker" - would either be attached to the rear of the train, or just come up against the guard's brake van's buffers. Then the banker's driver would whistle - using a series of long blasts and shorts. This told both the signalman and the driver of the train engine that he was ready. The train engine's driver would reply in similar fashion and, with signals at clear, they would set off in unison. If the banker was coupled to the train then, when it reached the top of the bank, the train would stop or come to a crawl for the banker to be uncoupled; if not, then the banker's driver would just ease off the regulator, allowing the train to continue on its way, with, of course, a whistled "goodbye".
The need to blare a train's whistle excessively loudly to be heard by the driver of a vehicle approaching a grade crossing has become a major disadvantage to the use of train whistles as a safety device and has caused much controversy to those living within earshot of the train's whistle. It has been documented that a train's whistle, when operating on compressed air, driving an exponential horn, has been measured at a higher decibel levels within the homes of nearby residents than within the cab of a vehicle sitting at the grade crossing.
Given the tonal design of the train whistle, the sound level, how often trains pass through a given community, the number of grade crossings in proximity, and the time of day (night) of occurrence, some feel that train whistles have a serious detrimental effect on the quality of life of community residents in a given area despite the gain in safety that sounding the horn provides to motorists. However, one FRA study that has very low statictical validity has shown that the frequency of grade crossing accidents increase in areas where quiet zones are in effect. The study fails to account for other factors that were also introduced at the same time which may have also accounted for the reduction in accidents during the same period the study measured. Additionally, the measurements were based on accidents at grade-crossings, which are very low numbers overall to begin with. A grade-crossing that had two accidents during the comparison years, that were contrasted with only one accident during the control period would statistically yield a high percentage-wise improvement in safety, when in reality, it was the difference in only one accident for that grade-crossing.
Conversely there are those who do not object to the train whistle, as they believe it provides an important safety feature. Some people even like the sound of the whistle, as it calls to mind a nostalgic era, as with the riverboats and their steam whistles and calliopes. However, no real studies have been performed by unbiased official entities to measure the real effects such noise has on a community.
Train whistles are used to communicate to other railroad workers on a train or to railroad workers in the yard. Different combinations of long and short whistles each have their own meaning. They are used to pass instructions, as a safety signal, and to warn of impending movements of a train. Despite the advent of modern radio communication, many of these whistle signals are still used today. (See also Train horn (Common Horn Signals).)
Signals are illustrated by an "o" for short sounds, and "-" for longer sounds.
|Sequence||What it means|
|Succession of short sounds||Used when an emergency exists, or if persons or livestock are on the track.|
|–||When train is stopped. The air brakes are applied and pressure is equalized.|
|– –||Train releases brakes and proceeds.|
|o o||Acknowledgment of any signal not otherwise provided for.|
|o o o||When train is stopped: means backing up, or acknowledgment of a hand signal to back up.|
|o o o o||Request for a signal to be given or repeated if not understood.|
|– o o o||Instruction for flagman to protect rear of train.|
|– – – –||Flagman return from the west or south.|
|– – – – –||Flagman return from the east or north.|
|– – o –||Train is approaching public grade crossing(s). This is known as Rule 14L in almost all railroad operating rules.|
|– o||Inspect the brake system for leaks or sticking brakes.|
Not all railroads use the exact same whistle signals or assign the same meanings. Some railroads will use their own variations of the above. A few of the signals are obsolete because the workers they were used to communicate with (such as flagman) are now obsolete.
In Norway, for example, the following whistle signals are used:
In Finland, the following are some of the signals used:
Excerpt: If you miss the train I'm on, You will know that I am gone. You can hear the whistle blow a hundred miles, A hundred miles, two hundred miles, three hundred miles, four hundred miles, You can hear the whistle blow five hundred miles.
In popular and folk culture, train whistles are often associated with loneliness or hard luck, because of the association of trains with transients and hobos who often wait outside the train station and run and jump on to ride the railcars as they just begin moving out of the station. The book "Hear That Lonesome Whistle Blow" is an example.
Furthermore, minor chords (like that of a train whistle) are said to have a melancholy sound. Minor(.wav)Additionally, steam whistles (the traditional sounding mechanism of train whistles) tend to waver in pitch, and thus make more of a crying or wailing sound, that further adds to the lonesome nature of the whistle. Waver(.wav) Even the modern compressed-air whistle wavers in pitch much more than does a car horn, and the sound of the whistle is more "throaty" and windy (more like a pan flute or calliope) than other signalling devices like automobile horns. Throaty(.wav)
Lastly, train stations were (and, to some degree still are) associated with the departure of loved ones, and the sadness of saying goodbye. To the extent that the sound of a train whistle is unique, and somewhat symbolic of long distance travel, it has come to contextualize itself as mournful and melancholy. Sad(.wav)