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{{globalize}} {{Sprotected}}
] locomotive equipped with a Leslie model S3L air horn. These particular horns have been nicknamed 'Conrail Horns' by fans.]] ] locomotive equipped with a Leslie model S3L air horn. These particular horns have been nicknamed 'Conrail Horns' by fans.]]
'''Train horns''' are audible warning devices found on most diesel and electric ]s. They most commonly are used for internal communication between train staff, i.e. during ] operations, and for warning purposes to members of the public who are near on on the rail line, for example on a ]. '''Train horn'''s are audible warning devices found on diesel and electric ]s.


''(Note that this article deals with locomotive air horns as used throughout ]. For those used elsewhere, please refer to the ] article.)''
==History and background==
==History and Background==


As diesel locomotives began to replace steam on many ]s, it was realized that the new locomotives were unable to utilize the ]s then in use. Early ] locomotives were initially fitted with truck horns, but these were found to be unsuitable, and so the air horn design was modified for railroad use. As diesel locomotives began to replace steam
on North American ]s, it was realized that the new locomotives were unable to utilize the ]s then in use.
Early ] locomotives
were initially fitted with truck horns, but these were found to be unsuitable, and so the air horn design was modified for railroad use.


==Operation== ==Operation==


Train horns are operated by compressed
Classic train horns are operated by compressed air, typically 130-145 ] (9-10 ]), and fed from a locomotive main air ]. On American locomotives built prior to the early ], they are actuated by a manual lever or pull-cord. Current American locomotives, as well as European models built since the mid-], make use of pushbutton controls.
air, typically 130-145 ], and fed from a
locomotive main air ]. On locomotives built prior to the
early ], they are actuated
by a manual lever or pull-cord.
Locomotives built today make use of
pushbutton controls.


The basic operation of a train horn, or most any air horn for that matter, is that the air flow throughout The basic operation of a train
horn, or most any air horn for that
matter, is that the air flow throughout
the horn causes ], producing sound waves. Oscillation in a train horn is accomplished via a ]. When air is applied to the horn, the diaphragm begins to vibrate. Since the position of the diaphragm at any given moment during the vibration will allow more or less air through the horn, the constant oscillation of the diaphragm causes "waves" of air which in turn produce audible sound. the horn causes ], producing sound waves. Oscillation in a train
horn is accomplished via a ]. When air is
applied to the horn, the diaphragm
begins to vibrate. Since the position
of the diaphragm at any given moment
during the vibration will allow more
or less air through the horn, the
constant oscillation of the diaphragm causes "waves" of air which in turn
produce audible sound.


The configuration and dimensions of the bell ("''bell''" being the correct term for the trumpet assembly) determine the frequency produced (measured in ]), and hence, the ]. The configuration and dimensions
of the bell ("''bell''" being the
correct term for the trumpet assembly) determine the frequency produced
(measured in ]), and hence, the ].


Many early three and five-note train horns were designed to play basic musical ]. Many early three and five-note train
horns were designed to play basic musical ].


==Manufacturers== ==Manufacturers==
=== North America ===


There have been six major manufacturers of air horns for railroad use in North America. Of these, only Airchime, Ltd. and Leslie Controls, Inc. remain today. There have been six major manufacturers of air horns for railroad use in North America. Of these, only Airchime, Ltd. and Leslie Controls, Inc. remain today:

===Gustin Bacon Mfg. Co.===


====Gustin Bacon Mfg. Co.====
''The Gustin Bacon Mfg. Co.'' of ] offered airhorns for use on railroad equipment prior to the ]. ''The Gustin Bacon Mfg. Co.'' of ] offered airhorns for use on railroad equipment prior to the ].


====The American Strombos Co.==== ===The American Strombos Co.===
] ]
''The American Strombos Co.'' of ] (later to become ''The American Strombos Co.'' of ] (later to become
Line 34: Line 60:
]s ''(for example the ])''. ]s ''(for example the ])''.


====Westinghouse Air Brake Co.==== ===Westinghouse Air Brake Co.===


''Westinghouse'' (under their '']'' subsidiary) was the first to offer airhorns specifically for railroad equipment, going ''Westinghouse'' (under their '']'' subsidiary) was the first to offer airhorns specifically for railroad equipment, going
Line 42: Line 68:
horns for the North American market. horns for the North American market.


====Leslie Controls, Inc.==== ===Leslie Controls, Inc.===
].]] ].]]
''Leslie Controls'' originally began horn production by obtaining the rights to manufacture the ] line of ''Tyfon'' brand airhorns, marketing these for railroad use in the early ''Leslie Controls'' originally began horn production by obtaining the rights to manufacture the ] line of ''Tyfon'' brand airhorns, marketing these for railroad use in the early
]. Their model ''A200'' series
]. Their model ''A200'' series graced the rooftops of countless locomotives, such as the legendary ], as well as thousands of ] ] and ]. Leslie would later introduce their own line of multi-note airhorns, known as the ''Chime-Tone'' series, in direct competition with Nathan-AirChime.
graced the rooftops of countless locomotives, such as the legendary ], as well as thousands of
] ] and ]. Leslie would later introduce their
own line of multi-note airhorns, known
as the ''Chime-Tone'' series, in
direct competition with Nathan-AirChime.


Poor sales of the Chime-Tones (due to the
Poor sales of the Chime-Tones (due to the added weight of the assembled horn, as well as requiring an ample air supply) led the Leslie Co. to develop the ''SuperTyfon'' line of horns utilizing interchangeable parts. Horns were offered in single, dual, triple, quad (in the case of ] locomotives), and five note variants. Until recently, ''SuperTyfon'' products were the mainstay of almost all railroad motive power in the ].
added weight of the assembled horn, as
] of the ].]]
well as requiring an ample air supply) led
the Leslie Co. to develop the ''SuperTyfon'' line of horns utilizing interchangeable
parts. Horns were offered in single,
dual, triple, quad (in the case of ] locomotives), and
five note variants. Until recently, ''SuperTyfon'' products were
the mainstay of almost all railroad
motive power in the ].
] of the ].]]
]s.]] ]s.]]


====Nathan-AirChime, Ltd.==== ===Nathan-AirChime, Ltd.===
].]] ].]]
] paint scheme.]] ] paint scheme.]]
''Nathan-AirChime, Ltd.'' got their start in train horn production through the work of ] in ]. Prior to the early ], locomotives were equipped with airhorns that sounded but a single note. ''Nathan-AirChime, Ltd.'' got their start
in train horn production through the work
of ] in ]. Prior
to the early ], locomotives were equipped with airhorns that sounded
but a single note.


Swanson set out to change this by developing a horn which could almost mimic the sound of a classic steam Swanson set out to change this by
developing a horn which could almost
mimic the sound of a classic steam
whistle. Using ancient Chinese ], Swanson produced the six-note model ''H6''. However pleasant the horn may have sounded, this was impractical for railroad use due to its relatively large size and weight. It should be noted that since railroad equipment operates in areas restricted by physical clearance, the difference of only a few inches may prohibit that equipment from operating on the line in question. Swanson would later refine the design into the ''H5''. whistle. Using ancient Chinese ], Swanson produced the six-note model ''H6''. However pleasant the horn
may have sounded, this was impractical
for railroad use due to its relatively
large size and weight. It should be
noted that since railroad equipment
operates in areas restricted by
physical clearance, the difference
of only a few inches may prohibit
that equipment from operating on the
line in question. Swanson would later
refine the design into the ''H5''.
As the model number indicates, this horn sounded a five-note, adjustable chord. As the model number indicates, this horn sounded a five-note, adjustable chord.


Nathan-AirChime has since gone on to perfect their horn design with the ''M'' (]), ''P'' (]), and ''K'' (]) series, respectively. Nathan-AirChime has since gone on to
perfect their horn design with the ''M'' (]), ''P'' (]), and ''K'' (]) series, respectively.


====Prime Manufacturing, Inc.==== ===Prime Manufacturing, Inc.===
] ]
''Prime Manufacturing, Inc.'' had produced locomotive appliances for many years prior to their entry into the horn market in the early ]. Basically a ] of the Leslie ''SuperTyfon'' design (due to a Leslie ] expiration), though the Prime versions employed heavier castings and sounded a somewhat richer ] as a result. Sales were brisk (] was a notable customer), and unable to compete with offerings from Leslie and AirChime, as well as ever-stringent government regulation, Prime left the horn market in ]. ''Prime Manufacturing, Inc.'' had produced locomotive appliances for many years
prior to their entry into the horn
market in the early ]. Basically a ] of
the Leslie ''SuperTyfon'' design (due
to a Leslie ] expiration), though
the Prime versions employed heavier
castings and sounded a somewhat richer ] as a result. Sales were
brisk (] was a notable customer), and unable to
compete with offerings from Leslie and AirChime, as well as ever-stringent
government regulation, Prime left the
horn market in ].


==Location and placement== ==Location and placement==
Line 75: Line 141:
<gallery> <gallery>
Image:S3L_ATSF.jpg|Leslie model S3L air horn mounted atop the cab roof of a Santa Fe locomotive in the classic location. Image:S3L_ATSF.jpg|Leslie model S3L air horn mounted atop the cab roof of a Santa Fe locomotive in the classic location.
Image:P5_NS.jpg|On many locomotives with high short hoods, such as this Norfolk Southern ], the air horn can be located away from the operating cab. Image:P5_NS.jpg|On many locomotives with high short hoods, such as this Norfolk Southern ] -- the air horn can be located away from the operating cab.
Image:K5H_bracket.jpg|AirChime model K5H mounted on a custom bracket. Not only is the horn located here, but the air-operated bell as well. Image:K5H_bracket.jpg|AirChime model K5H mounted on a custom bracket. Not only is the horn located here, but the air-operated bell as well.
Image:K5HL_GEVO.jpg|On newer locomotives, the horn is mounted atop the engine compartment due to complaints from train crews. However, ] performance suffers, and the sound is often muffled. Image:K5HL_GEVO.jpg|On newer locomotives, the horn is mounted atop the engine compartment due to complaints from train crews. Unfortunately, ] performance suffers, and the sound is often muffled.
</gallery> </gallery>
<br style="clear:both;"> <br style="clear:both;">


==Common horn signals== ==Common Horn Signals==
The meaning of horn signals varies from country to country. Most countries with large former or current state-owned railway networks, like ], ] or ], use standardized meanings of horn signals on their networks, whilst in other countries, for example the ], meanings of horn signals can vary between railway operators.
===United States===
Railroads are required by a variety of state and federal laws to sound horns in advance of all crossings. Horns are sounded for safety reasons, namely, to warn of approaching trains.


Railroads are required by a variety of state and federal laws to sound horns in advance of all crossings. Horns are sounded for safety reasons, namely, to warn of approaching trains. (See also ] for traditional horn and whistle signals.)
The following are the required horn signals listed in the operating rules of most railroads, along with their meanings. Signals are illustrated by an "'''-'''" for short sounds, and "'''.'''" for longer sounds.

The following are the required horn signals listed in the operating rules of most North American railroads, along with their meanings. Signals are illustrated by an "'''o'''" for short sounds, and "'''-'''" for longer sounds. ''(Note that these signals and their meanings are updated to reflect modern practice.)''


{| class="toccolours" {| class="toccolours"
! bgcolor=#CCCCCC | Rule
! bgcolor=#CCCCCC | Sequence ! bgcolor=#CCCCCC | Sequence
! bgcolor=#CCCCCC | Meaning ! bgcolor=#CCCCCC | Indication
|- |-
|14 (a)
|'''Succession of short sounds'''
|'''o'''
|Used when an emergency exists, or if persons or livestock are on the track.
|Applying air brakes while standing.
|- |-
|14 (b)
|'''.'''
|'''- -'''
|When train is stopped. The air brakes are applied and pressure is equalized.
|*Proceeding/releasing air brakes.
|- |-
|14 (g)
|'''. .'''
|'''o o'''
|Train releases brakes and proceeds.
|Acknowledging any signal not otherwise provided for.
|- |-
|14 (h)
|'''- -'''
|'''o o o'''
|Acknowledgment of any signal not otherwise provided for.
|*Backing up.
|- |-
|14 (j)
|'''- - -'''
|'''o o o o'''
|When train is stopped: means backing up, or acknowledgment of a hand signal to back up.
|Calling for signals.
|- |-
|14 (l)
|'''- - - -'''
|'''- - o -'''
|Request for a signal to be given or repeated if not understood.
|Approaching public crossings at grade.
|- |-
|14 (o)
|'''. - - -'''
|'''o -'''
|Instruction for flagman to protect rear of train.
|Inspect train for a leak in brake pipe system or for brakes sticking.
|- |-
|14 (p)
|'''. . . .'''
|'''Succession of sounds'''
|Flagman return from the west or south.
|Warning to people and/or animals.
|- |-
|14 (q)
|'''. . . . .'''
|'''- o'''
|Flagman return from the east or north.
|When running against the current of traffic: 1. Approaching stations, curves, or other points where view may be obscured: and 2. Approaching passenger or freight trains and when passing freight trains.
|- |-
|'''. . - .'''
|Train is approaching public grade crossing(s). This is known as ''Rule 14L'' in almost all railroad operating rules.
|-
|'''. -'''
|Inspect the brake system for leaks or sticking brakes.
|} |}
===Germany===
Horn signals are regulated in the ''Zp'' category of the ]. Their most common use today is when approaching a ] that lacks barriers, and for warning purposes.


'''Exception:''' Engine horn signals required by rules 14 (b) and 14 (h) do not apply after momentary stops in continuous switching movements.
Common signals are:<ref>{{de icon}}{{cite web|url=http://www.stellwerke.de/signal/deutsch/zp.html|title=www.stellwerke.de - Signalsystem in Deutschland|accessdate=2007-02-05}}</ref>


==Audio Samples==
{| class="toccolours"
! bgcolor=#CCCCCC | Sequence
! bgcolor=#CCCCCC | Meaning
|-
|'''-'''
|Zp 1 - Generic "Attention" signal.
|-
|'''.'''
|Zp 2 - Tighten handbrakes.
|-
|'''. .'''
|Zp 3 - Strongly tighten handbrakes.
|-
|'''- -'''
|Zp 4 - Loosen handbrakes
|-
|'''... ... ...'''
|Zp 5 - Emergency. Brake immediately.
|-
|'''- . -'''
|Zp 11 - Come. Used to call out for train staff.
|}


The following audio files are in ] format:
==Government ruling on the use of train horns==


* (306])
On April 27, 2005, the ] (FRA), which enforces rail safety regulations, published the final rule on the use of locomotive horns at highway-rail grade crossings. Effective June 24, 2005, the rule requires that locomotive horns be sounded at all public grade crossings 15-20 seconds before entering a crossing, but not more than one-quarter mile (400 m) in advance. This rule applies when the train speed is below 45 ] (70 km/h). At 45 mph or above, trains are still required to sound their horn at the designated location (usually marked with a ]).


* (256kB)
The pattern for blowing the horn remains two long, one short, and one long. This is to be repeated as necessary until the lead locomotive fully occupies the crossing. Locomotive engineers retain the authority to vary this pattern as necessary for crossings in close proximity, and will be allowed to sound the horn in emergency situations no matter where the location.


* (340kB)
A ban on sounding locomotive horns in ] was ordered removed by the FRA after it was shown that the accident rate ''doubled'' during the ban. The new ruling preempts any state or local laws regarding the use of the train horn at public crossings. This also provides public authorities the option to maintain and/or establish quiet zones provided certain supplemental or alternative safety measures are in place, ''and the crossing accident rate meets government standards''.


* (197kB)
==Train horns and popular culture==
] modified with the addition of a locomotive horn and bell. This is the preferred setup of many train horn collectors.]]


* (209kB)
Fitting a train horn to ]s or an ] has become the current ] of many vehicle customizers.{{fact}} One should keep in mind that train horns are extremely powerful devices, and use of one while in motor vehicle traffic can cause an accident. They may also violate local noise ]s. Recent years have seen an increase of horn theft from railroad property, it is believed that the great majority of these crimes are perpetuated for the benefit of vehicle customizers and truckers.{{fact}}


* (174kB)
On the other hand, there are those who collect train horns for their rarity and nostalgic value. Such items can command high prices among collectors. One rule of thumb may be that if the horn(s) are mounted prominently on the vehicle, the owner is a responsible collector, whilst those of the faddish vehicle customizer are generally hidden from view on the vehicle in question.


* (194kB)
Due to the encroachment of development, some ] dwellers (known derisively as ]s and ]) have opposed the railroad use of the air horn as a trackside warning device. This despite
the fact that in most locations, the railroad had been established long before the development sprang up.


* (255kB)
Residents in some communities have attempted to establish ''quiet zones'', in which train crews are instructed not to sound their horns, except in case of emergency. Given the speed at which many trains travel, as well as the disparity in ] between railroad equipment and an automobile or truck, incidents often occur without warning. The effects of a train colliding with an errant automobile have been likened to that same automobile striking an empty soda can.{{fact}}


* (221kB)
==External links==


''(Audio files courtesy of Chris Moyer''
* - Complete text on the ruling concerning the use of locomotive horns at highway-rail grade crossings.
''and )''


==Government ruling on the use of train horns==
* - The original online spotters guide to diesel locomotive horns as used throughout the United States and Canada. Fully illustrated, with audio samples and background information on each horn.


On April 27, 2005, the ] (FRA), which enforces
* - Collectors guide to locomotive horns. Includes information on identifying rare makes and models, restoration, and maintenance.
rail safety regulations, published the
final rule on the use of locomotive horns
at highway-rail grade crossings. Effective June 24, 2005, the rule requires that locomotive horns be sounded at all public
grade crossings 15-20 seconds before
entering a crossing, but not more than
one-quarter mile in advance. This rule
applies when the train speed is below
45 ]. At 45 mph or
above, trains are still required to
sound their horn at the designated
location (usually marked with a
]).


The pattern for blowing the horn
* - Makers of SuperTyfon brand air horns for rail, marine, and industrial use.
remains two long, one short, and one
long. This is to be repeated as necessary
until the lead locomotive fully
occupies the crossing. Locomotive
engineers retain the authority to
vary this pattern as necessary for
crossings in close proximity, and
will be allowed to sound the horn
in emergency situations no matter
where the location.


A ban on sounding locomotive horns
* - Offers air horns and whistles for both heavy and ] applications.
in ] was ordered removed
by the FRA after it was shown that
the accident rate ''doubled'' during
the ban. The new ruling preempts any
state or local laws regarding the use
of the train horn at public crossings.
This also provides public authorities
the option to maintain and/or establish
quiet zones provided certain supplemental
or alternative safety measures are in place, ''and the crossing accident rate
meets government standards''.


==Train Horns and Popular Culture==
] modified with the addition of a locomotive horn and bell. This is the preferred setup of many train horn collectors.]]


Fitting a train horn to ]s or
===Audio samples===
an ] has become the current ]
of many vehicle customizers. One should
keep in mind that train horns are extremely powerful devices, and use of one while
in motor vehicle traffic can cause an
accident. They may also violate local noise ]s. Recent years have seen an increase of horn theft from railroad
property, it is believed that the great majority of these crimes are perpetuated
for the benefit of vehicle customizers and truckers.


On the other hand, there are those who
The following audio files are in ] format:
collect train horns for their rarity and nostalgic value. Such items can command
high prices among collectors. One rule of
thumb may be that if the horn(s) are
mounted prominently on the vehicle, the
owner is a responsible collector, whilst
those of the faddish vehicle customizer
are generally hidden from view on the
vehicle in question.


Due to the encroachment of development, some ] dwellers (known derisively
* (306])
as ]s and ]) have
opposed the railroad use of the air horn
as a trackside warning device. This despite
the fact that in most locations, the railroad had been established long before the development sprang up.


Residents in some communities have attempted
* (256kB)
to establish ''quiet zones'', in which
train crews are instructed not to sound
their horns, except in case of emergency.
Given the speed at which many trains
travel, as well as the disparity in
] between railroad equipment and
an automobile or truck, incidents often
occur without warning. The effects of
a train colliding with an errant automobile have been likened to that same automobile striking an empty soda can.


==References, Sources, and External Links==
* (340kB)


* CSX Operating Rules ''(Effective October 1, 2004)''
* (197kB)


* - Complete text on the ruling concerning the use of locomotive horns at highway-rail grade crossings.
* (209kB)


* - The original online spotters guide to diesel locomotive horns as used throughout the United States and Canada. Fully illustrated, with audio samples and background information on each horn.
* (174kB)


* - Collectors guide to locomotive horns. Includes information on identifying rare makes and models, restoration, and maintenance.
* (194kB)

* - Makers of SuperTyfon brand air horns for rail, marine, and industrial use.

* - Offers air horns and whistles for both heavy and ] applications.


* (255kB)


* (221kB)
{{unref|date=February 2007}}
] ]
] ]

Revision as of 17:59, 5 February 2007

File:ElizabethNJ.jpg
Conrail locomotive equipped with a Leslie model S3L air horn. These particular horns have been nicknamed 'Conrail Horns' by fans.

Train horns are audible warning devices found on diesel and electric locomotives.

(Note that this article deals with locomotive air horns as used throughout North America. For those used elsewhere, please refer to the Train whistle article.)

History and Background

As diesel locomotives began to replace steam on North American railroads, it was realized that the new locomotives were unable to utilize the steam whistles then in use.

Early internal-combustion locomotives were initially fitted with truck horns, but these were found to be unsuitable, and so the air horn design was modified for railroad use.

Operation

Train horns are operated by compressed air, typically 130-145 psi, and fed from a locomotive main air reservoir. On locomotives built prior to the early 1990s, they are actuated by a manual lever or pull-cord. Locomotives built today make use of pushbutton controls.

The basic operation of a train horn, or most any air horn for that matter, is that the air flow throughout the horn causes oscillation, producing sound waves. Oscillation in a train horn is accomplished via a diaphragm. When air is applied to the horn, the diaphragm begins to vibrate. Since the position of the diaphragm at any given moment during the vibration will allow more or less air through the horn, the constant oscillation of the diaphragm causes "waves" of air which in turn produce audible sound.

The configuration and dimensions of the bell ("bell" being the correct term for the trumpet assembly) determine the frequency produced (measured in hertz), and hence, the fundamental.

Many early three and five-note train horns were designed to play basic musical chords.

Manufacturers

There have been six major manufacturers of air horns for railroad use in North America. Of these, only Airchime, Ltd. and Leslie Controls, Inc. remain today:

Gustin Bacon Mfg. Co.

The Gustin Bacon Mfg. Co. of Kansas City, MO offered airhorns for use on railroad equipment prior to the Second World War.

The American Strombos Co.

An air horn manufactured by Strombos. Used on early locomotives as well as trucks.

The American Strombos Co. of Philadelphia, PA (later to become known as Buell) sold modified truck horns for rail use. They were often installed on small locomotives and railcars (for example the Doodlebugs).

Westinghouse Air Brake Co.

Westinghouse (under their WABCO subsidiary) was the first to offer airhorns specifically for railroad equipment, going as far back as the 1910s. Their model E2 was known by many for the deep, commanding tone it produced. Overshadowed later on by their post-WWII competitors, WABCO no longer produces horns for the North American market.

Leslie Controls, Inc.

Leslie model A200-156 locomotive air horn, used in the early days of dieselization.

Leslie Controls originally began horn production by obtaining the rights to manufacture the Kockums Mekaniska Verkstad line of Tyfon brand airhorns, marketing these for railroad use in the early 1930s. Their model A200 series graced the rooftops of countless locomotives, such as the legendary Pennsylvania Railroad GG1, as well as thousands of EMD E and F-units. Leslie would later introduce their own line of multi-note airhorns, known as the Chime-Tone series, in direct competition with Nathan-AirChime.

Poor sales of the Chime-Tones (due to the added weight of the assembled horn, as well as requiring an ample air supply) led the Leslie Co. to develop the SuperTyfon line of horns utilizing interchangeable parts. Horns were offered in single, dual, triple, quad (in the case of Amtrak's SDP40F locomotives), and five note variants. Until recently, SuperTyfon products were the mainstay of almost all railroad motive power in the United States.

Leslie model S5T, widely regarded by aficionados as the 'king of horns'. This specimen is painted in the gray scheme of the Seaboard System Railroad.
Leslie model S3L, at one time the most common diesel locomotive horn used on North American railroads. This example features a reversed bell for use on road switchers.

Nathan-AirChime, Ltd.

An early Nathan-AirChime model P5 locomotive air horn, later versions are used by such railroads as the Norfolk Southern.
AirChime model K3L, shown here in a wonderful Auburn University paint scheme.

Nathan-AirChime, Ltd. got their start in train horn production through the work of Robert Swanson in 1949. Prior to the early 1950s, locomotives were equipped with airhorns that sounded but a single note.

Swanson set out to change this by developing a horn which could almost mimic the sound of a classic steam whistle. Using ancient Chinese musical theory, Swanson produced the six-note model H6. However pleasant the horn may have sounded, this was impractical for railroad use due to its relatively large size and weight. It should be noted that since railroad equipment operates in areas restricted by physical clearance, the difference of only a few inches may prohibit that equipment from operating on the line in question. Swanson would later refine the design into the H5. As the model number indicates, this horn sounded a five-note, adjustable chord.

Nathan-AirChime has since gone on to perfect their horn design with the M (1950), P (1953), and K (1954) series, respectively.

Prime Manufacturing, Inc.

File:PrimePM920.jpg
Prime model PM920 locomotive air horn, compare this with the Leslie S3L shown above.

Prime Manufacturing, Inc. had produced locomotive appliances for many years prior to their entry into the horn market in the early 1970s. Basically a derivative of the Leslie SuperTyfon design (due to a Leslie patent expiration), though the Prime versions employed heavier castings and sounded a somewhat richer tone as a result. Sales were brisk (Union Pacific was a notable customer), and unable to compete with offerings from Leslie and AirChime, as well as ever-stringent government regulation, Prime left the horn market in 1999.

Location and placement

As many people do with their personal vehicles, railroads order locomotives with many different options in order to suit their operating and maintenance practices.

Horns are no exception, and railroad mechanical forces mount these on locomotives where they are deemed most effective at projecting sound. Below are a few images depicting the most common mounting locations:



Common Horn Signals

Railroads are required by a variety of state and federal laws to sound horns in advance of all crossings. Horns are sounded for safety reasons, namely, to warn of approaching trains. (See also Train whistle (Whistle code) for traditional horn and whistle signals.)

The following are the required horn signals listed in the operating rules of most North American railroads, along with their meanings. Signals are illustrated by an "o" for short sounds, and "-" for longer sounds. (Note that these signals and their meanings are updated to reflect modern practice.)

Rule Sequence Indication
14 (a) o Applying air brakes while standing.
14 (b) - - *Proceeding/releasing air brakes.
14 (g) o o Acknowledging any signal not otherwise provided for.
14 (h) o o o *Backing up.
14 (j) o o o o Calling for signals.
14 (l) - - o - Approaching public crossings at grade.
14 (o) o - Inspect train for a leak in brake pipe system or for brakes sticking.
14 (p) Succession of sounds Warning to people and/or animals.
14 (q) - o When running against the current of traffic: 1. Approaching stations, curves, or other points where view may be obscured: and 2. Approaching passenger or freight trains and when passing freight trains.

Exception: Engine horn signals required by rules 14 (b) and 14 (h) do not apply after momentary stops in continuous switching movements.

Audio Samples

The following audio files are in .WAV format:

(Audio files courtesy of Chris Moyer and Trainhorns.net)

Government ruling on the use of train horns

On April 27, 2005, the Federal Railroad Administration (FRA), which enforces rail safety regulations, published the final rule on the use of locomotive horns at highway-rail grade crossings. Effective June 24, 2005, the rule requires that locomotive horns be sounded at all public grade crossings 15-20 seconds before entering a crossing, but not more than one-quarter mile in advance. This rule applies when the train speed is below 45 mph. At 45 mph or above, trains are still required to sound their horn at the designated location (usually marked with a whistle post).

The pattern for blowing the horn remains two long, one short, and one long. This is to be repeated as necessary until the lead locomotive fully occupies the crossing. Locomotive engineers retain the authority to vary this pattern as necessary for crossings in close proximity, and will be allowed to sound the horn in emergency situations no matter where the location.

A ban on sounding locomotive horns in Florida was ordered removed by the FRA after it was shown that the accident rate doubled during the ban. The new ruling preempts any state or local laws regarding the use of the train horn at public crossings. This also provides public authorities the option to maintain and/or establish quiet zones provided certain supplemental or alternative safety measures are in place, and the crossing accident rate meets government standards.

Train Horns and Popular Culture

Chevrolet Astro modified with the addition of a locomotive horn and bell. This is the preferred setup of many train horn collectors.

Fitting a train horn to trucks or an SUV has become the current fad of many vehicle customizers. One should keep in mind that train horns are extremely powerful devices, and use of one while in motor vehicle traffic can cause an accident. They may also violate local noise ordinances. Recent years have seen an increase of horn theft from railroad property, it is believed that the great majority of these crimes are perpetuated for the benefit of vehicle customizers and truckers.

On the other hand, there are those who collect train horns for their rarity and nostalgic value. Such items can command high prices among collectors. One rule of thumb may be that if the horn(s) are mounted prominently on the vehicle, the owner is a responsible collector, whilst those of the faddish vehicle customizer are generally hidden from view on the vehicle in question.

Due to the encroachment of development, some suburban dwellers (known derisively as NIMBYs and CAVE People) have opposed the railroad use of the air horn as a trackside warning device. This despite the fact that in most locations, the railroad had been established long before the development sprang up.

Residents in some communities have attempted to establish quiet zones, in which train crews are instructed not to sound their horns, except in case of emergency. Given the speed at which many trains travel, as well as the disparity in mass between railroad equipment and an automobile or truck, incidents often occur without warning. The effects of a train colliding with an errant automobile have been likened to that same automobile striking an empty soda can.

References, Sources, and External Links

  • CSX Operating Rules (Effective October 1, 2004)
  • Five Chime Consultants - The original online spotters guide to diesel locomotive horns as used throughout the United States and Canada. Fully illustrated, with audio samples and background information on each horn.
  • Trainhorns.net - Collectors guide to locomotive horns. Includes information on identifying rare makes and models, restoration, and maintenance.
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