Identifying Defect Detectors

CSX Talker

CSX has developed an in-house talker unit in lieu of utilizing commercially available products like the Progress Rail Micro Talker or the STC iCUBE. These units can be found on Wheel Impact (WILD) detectors and high/wide clearance detectors throughout the CSX system.

The female voice heard on these units is the same as used on their radio-controlled remote switches & radio-activated crossings/warning devices.

CSX Talker - WILD

Of all of the detector manufacturers, Devtronics models are among the hardest to pin down, particularly on CSX where the first talking detectors extended back to the Seaboard Air Line days.

The 68178, 68278, and MA-1 models all utilized a 9 track tape that used audio tones for timing of words. As the tapes were recorded as the units were replaced, a variety of different voices emerged, and it can be difficult to discern a model solely from the voice. In the examples on the right, you can hear instances in which the same voice is used for all 3 of these models.

The TSA3000 and CMA02 models were newer (compared to the previous 3) hot bearing-capable units. The TSA3000 wasn't a very common model on CSX with only a few dozen, while the CMA02 numbered into the hundreds and lasted much longer.

The UT-1 and later the S.C.A.T. (Supervisory Control Alarm Telemetry) units were not capable of detecting hot bearings, and were thus utilized primarily as dragging equipment or high car detectors.

UT-1 - Early Version
Harmon Industries

Harmon has been around for a long time, with many talking defect detector models. However, most of these units share the same two voices, making them all but impossible to differentiate without seeing what's inside the bungalow. Models sharing the same two voices include the Mini Talker II, Model 24, Model 32, Model 46, and Model 75.

One notable variation were Southern Pacific's custom female voices. The first voice (see Southern Pacific #1) was widely used across the system, while the second voice (see Southern Pacific #2) was only heard on the SPCSL line linking Chicago to St. Louis.

The only Harmon unit with a voice unique to itself is the Cyberscan 2000, introduced in the mid 1990s. However, CN elected to have their units utilize a custom Canadian male voice.

Harmon - Standard Voice
Harmon - Alternate Voice
Harmon - Southern Pacific #1
Harmon - Southern Pacific #2
Harmon Cyberscan 2000 - Standard Voice
Harmon Cyberscan 2000 - Canadian Voice
Progress Rail/GE Transporation Systems

The well known voice of Randy Goyer can be heard on MicroHBD & Micro Talker units all across North America. Little has changed with the audio of these units since their debut by GE Transportation Systems in the early 2000s, although the units have undergone many internal upgrades.

For the trained ear, you may be able to discern early GE Micro Talkers from more contemporary products. You can hear an ever so slight pauses between the word "track" and the track number, as well as between the letters in "CSX." Additionally, these units say "axles" while MicroHBD units say "axle" (singular). Unfortunately, newer Micro Talkers have no discernable difference in voice and can only be identified by their functionality as found in an employee timetable.

Norfolk Southern often utilizes Progress Rail Micro Talkers in conjunction with their Stress State Detectors - these are easily identified, as they generally say "NS" instead of "Norfolk Southern" and "MP" instead of "Milepost." However, NS Micro Talkers used in other roles (such as a dragging equipment detector) use identical speech patterns as their MicroHBD units.

As with previous models, CN has opted to use a custom Canadian male voice for their defect detectors. Note that CN's Sentry 2100s and MicroHBDs share the same voice - see our Canadian National page to learn how to tell them apart.

GE Micro Talker - Early
Progress Rail MicroHBD - Current
Progress Rail Micro Talker - NS SSD
Progress Rail MicroHBD - Canadian Voice
Servo Corp.

Servo had a long history of defect detectors, although only the last few models were able to talk as-built: the 9000 & the 9909. The unmistakable voice is often referred to as the "Speak & Spell" model by railfans.

However, things get complicated when looking trying to figure out what's in the bungalow by the voice on the radio. Servo's detectors are modular in nature, and many were retrofitted with talkers after the fact. As far as Servo voices go, Servo introduced a ServoTalk device to give older detectors this functionality.

Union Pacific's System 9000 units utilized a female voice that is just as robotic-sounding as the male voice.

A notable variation are Canadian Pacific's fleet of System 9000 detectors, which included a custom Canadian male voice. Ontario Northland also utilized the System 9000 with the same custom voice.

ServoTalk Talker (Tape Driven)
ServoTalk Talker (Solid State) - Installed on a Servo 8808
Servo 9000 - Standard Voice
Servo 9000 - Canadian Voice
Southern Technologies Corp.

Southern Technologies Corp. (STC) has 3 generations of hotbox detectors: the Sentry series, the SmartScan NG, and the SmartScan NG². Non-heat detecting models included certain Sentry models (black casing, whereas heat detecting models had a blue casing), the Small Talk, and the iCUBE.

The Sentry series and the SmartScan NG both use the same voice (that of an STC employee named Paul), which can make it easy to confuse the two. Early Sentry 2058s has a slightly muffled sound, a quicker pace, and the tendency to say "dot" instead of "point" for the milepost location. The Sentry 2058 commonly featured a female voice as well (that of STC employee named Linda), as heard commonly on Southern Pacific and Union Pacific. As of 2024, very few Sentry 2058 units remain in active service, and those that do are exclusively used on shortlines & regionals.

Later Sentry 2100s sound virtually identical to the SmartScan NG, but do have some subtle differences in their pace and the way they say certain numbers. Of note, Canadian National's Sentry 2100s utilize the same voice as their MicroHBD - see our Canadian National page to learn how to tell the difference between the two.

STC's Small Talk was a very simplistic, non-heat detecting unit. NS purchased many of these units to replace its aging ex-Conrail Parker DED 1GG units. They can be identified by their hybrid voice, which utilized the Sentry 2058-style voice for the railroad name & the word "milepost," while the rest of the message utilized the SmartScan NG-style voice. They also say "point" as opposed to "dot" for the milepost location. The Small Talk started production in the 1990s and was replaced by the iCube.

The SmartScan NG was introduced in 2004 as the successor to the Sentry 2100, so knowing which railroads utilized what units and the years they were in service is crucial to knowing what was actually in the bungalow. With that said, the SmartScan NG was a much more widely used model than the Sentry 2100. As of 2024, SmartScan NG units are being replaced en mass with SmartScan NG²s, but there are still a decent number out there.

In lieu of the SmartScan NG, Union Pacific opted to utilize a custom model from STC: the SmartScan IS. The SmartScan IS also utilizes Linda's voice, making it difficult to tell which model a detector is simply by its voice alone.

STC's iCUBE model is a small, non-heat detecting unit used for dragging equipment, slide fences, WILD detectors, etc. (similar in function to Progress Rail's Micro Talker). This model was introduced in the 2010s as a replacement for the Small Talk, and utilized the same voice as the SmartScan NG. Contemporary units use the same computer synthesized voice of the SmartScan NG².

The SmartScan NG² has a very distinctive computer-synthesized male voice and began appearing around 2017. Most railroads utilize a voice known as ‘Ryan’, while Canadian Pacific utilizes a bilingual voice known as ‘Matthew.’ While Union Pacific has opted to use this off-the-shelf unit this time around, they have chosen to utilize a computer-synthesized female voice (named ‘Linda’, but clearly different from the STC employee Linda's voice).

STC Sentry 2058 - Male Voice
STC Sentry 2058 - Female Voice
STC Sentry 2100 - Standard Voice
STC Sentry 2100 - Canadian Voice
STC Small Talk
STC SmartScan NG
STC SmartScan IS
STC SmartScan NG² - Male Voice 'Ryan'
STC SmartScan NG² - Male Voice 'Matthew'
STC SmartScan NG² - Female Voice 'Linda'
Spirit Solutions

Spirit Solutions was a short-lived manufacturer of thermal imaging-based defect detectors. Only one such installation is known (PT 241.0 on NS' Pittsburgh Line), which was subsequently replaced.

The voice heard here is that of Microsoft Sam, the default voice generator found on Windows 2000 and Windows XP. It is a common voice used by smaller manufacturers, so further verification is needed beyond the voice itself to identify what is actually in the signal bungalow.

Spirit Solutions MidNight Ridir

Detectors that we have not yet identified. Many are dragging equipment detectors, as they are simpler unit that are easy to build in-house, or were short-lived products from various companies.

  • Boston & Maine DED: Older model from at least the early 1990s, if not the 1980s.
  • Buckingham Branch DED: Newer model, possibly in-house. It uses the Microsoft Sam voice common to other oddball detectors (such as the Spirit Solutions MidNight Ridir).
  • Canadian National DED: No additional information available.
  • NS Trackside Analyzer: Believed to be NS' “Mark I” hot box detector. While the detector itself is a Servo 8909, it is unknown who manufactured the talker unit.
  • Reading & Northern DED - Male Voice: Newer model, possibly in-house.
  • Reading & Northern DED - Female Voice: Another newer model, again possibly in-house.
  • Union Pacific HBD-DED: Unknown if this is a custom Servo voice, or an Ensun Corp. talker (UP was known to be using their products with their detectors).

Both Ensun Corp. and Oregon Technical Products were known to have created custom talker units for non-talking defect detectors in the 1980s. However, we do not have enough evidence to indicate which is which at this time.

Boston & Maine DED
Buckingham Branch DED
Canadian National DED
NS Trackside Analyzer
Reading & Northern DED #1 - Male Voice
Reading & Northern DED #2 - Female Voice
Union Pacific HBD-DED

Zukinut's ZEPIC-DE dragging equipment detector is a discontinued model. Zukinut does, however, still produce derailment detectors.

Zukinut ZEPIC-DE