General Signals electronic bells

A General Signals electronic bell, as depicted on their site.

General Signals, Inc, based out of Evansville, IN, is a manufacturer of various equipment for railroad crossings, traffic signals, and other signalling. One such piece of equipment is their electronic bell, which has become a commonplace mainstay of North American railroad crossings and is one of the most common electronic bells. Their bells compete with Siemens, Western Cullen Hayes, NEG, and US&S in the North American electronic bell market.

## History and Design

In the early 1990s, a few manufacturers were experimenting with electronic bells. While electronic bells had already been established by the 1980s in Europe and the UK, they had not taken off in North America and the mechanical bell was still dominant. While mechanical bells offer superior sound, volume and longevity over the electronic bells, they also require more maintenance due to their moving parts and are heavy. General Signals, which had been in business since 1950, sought to create their own electronic bell to replace the mechanical bells. In 1991, the first of their bells began production, and saw use by a few different railroads during trial runs. Its main competition at the time was Associated Signal Company, who also were producing electronic bells by 1992. By 1995, the overall design of the bells had been finalized, and railroads began purchasing these bells for both new installs as well as to replace mechanical bells. However, most railroads continued to stick with the tried and true mechanical bells until the early 2000s, when electronic bells finally began to dominate. The overall design of General Signals' bell has changed little since 1995, with the only major change being the tone throughout the years. Today, the bell is most commonly used by BNSF, CPKC, NS, and CN. Various smaller railroads and commuter railroads are also fond of these bells. Norfolk Southern has the distinction of being one of the earliest adopters of these bells on a large scale, appearing on their crossings in the mid 1990s.

The design of every General Signals electronic bell is very simple. The bell is made out of PVC pipe, with the bell's circuit board and speaker housed inside of a cap on the top of the bell. The sound of a mechanical bell was recorded onto a chip on the circuit board using 16-bit technology, and when the bell is powered, this recording is played on a loop through the speaker. The board itself was produced by Tenelex Industries. The speaker is located on the underside of the board, facing downwards into the midsection of the bell. Three oval openings with mesh screens to keep debris out are where the sound is emitted, and a triangular surface is placed on the bottom of the midsection to project the sound in a specific direction, although the bell is largely omnidirectional with its sound. The bell sits on a protruding base, which can fit on 4 or 5-inch masts, and is where the siren's wiring terminals are located. Earlier GS bells used screws that were not rustproof, until GS switched to using rustproof screws by the early 2000s. Earlier GS bells also had protruding screws on top of the cap, but this was removed on later models due to water leaking through the screw holes and shorting out the circuit board. Every bell has a date code, as well as "GSI" imprinted into the base of the bell where the wiring terminals are.

The circuit board on GS bells have adjustable settings, including volume and ring speed. By default, the bells ring at 250 strokes per minute, output 85-95 dB, and operate on 7.5-17.5VDC. The ring speed is only adjustable on early GS bells, with the option being removed on Type-2 bells and beyond. GS offers special "loud tone" variants of their bell, as well as bells that can be adjusted between 3 volume settings.

Owing to the bell's success, other companies have copied the design of this bell and modified it to their own specifications. Such examples include the Safetran Type 2/NEG bells, as well as US&S' electronic bells.

There are four distinct "types" of General Signals bells, although these are community designations as GS themselves have never given the different types any specific designations.

### "Prototype" Early GS Bells (1991-1994)

The earliest bells produced by General Signals, often erroneously referred to by the community as "prototype" bells, were produced from 1991 until late 1994. Roughly 500 of these bells were made according to a former employee of the company, and had a distinctive design compared to later generations. The most significant difference is the base of the bell, which heavily resembles those used on mechanical bells, especially those made by Western Cullen Hayes, Inc. The openings on the bell are also much lower than later production GS bells. Various extra screws are also placed on the side of the bell. Some of these early bells have a unique tone, often including a distinct "knocking" sound as they ring, while others use an identical sound to the later Type-1 electronic bells. Despite their age, almost all being roughly 30 years old, several can still be found in service in both the United States and Canada. The bell would be discontinued in 1994 upon being redesigned into the Type-1 design. Some enthusiasts have begun referring to these as "Type-0" or "Early Type-1" bells to differentiate them from later models. This also avoids uprooting the naming scheme for General Signals bells that have been used for well over a decade.

Another "prototype" was created sometime in late 1994, and is presumed to be the earliest design for the modern GS bell. These heavily resemble later GS bells, but the midsection is significantly shorter, with the openings taking up most of the midsection. This was the introduction of the integrated base used on all later GS bells, replacing the base used on the early bells. Due to the lack of space in the midsection, the speaker sticks out past the openings and is clearly visible. These were only used by Southern Pacific, and in very few numbers. One survives in preservation today, and was likely redesigned due to the speaker being too exposed to the elements.

### Type-1 (1995-2001)

The Type-1 was the introduction of the modern design used by General Signals, and was a significant improvement of the design compared to the early design. The base from the 1994 prototype was reused, and the midsection was lengthened considerably to accommodate room for the speaker while shielding it from the elements. The openings were moved back to the lower area of the midsection, though placed slightly higher than the 1991 design. The PVC pipe was changed to green PVC pipe that was painted gray, which was supposed to be sturdier than gray PVC pipe. The GS Type-1 reused the non-knocking sound chip from the early bells, while the knocking sound chip was ultimately discarded. The Type-1 is visually distinguishable from later models by its slightly taller height, the non-rustproof screws used, and their tendency to become greenish in colour as the paint fades from UV exposure and weathering. They can be commonly found on crossing installs from the late 1990s. The Type-1 would be produced alongside the Type-2 until 2001, when it was discontinued. While many Type-1s were used in America, very few can be found elsewhere.

In Australia, many Type-1 bells have an external galvanised steel mesh screen, covering the entire midsection of the bell instead of only the openings. This secondary mesh screen is heavy duty and has many 1/4" diameter holes. In addition, the Australian market Type-1 e-bells were all loud tone variants, which had several more components on the circuit boards for more powerful amplification. Furthermore, they were also fitted with volume potentiometers on the front face of the top cap, however these were all removed and replaced with a nut and bolt due to weather sealing issues. Several of these Australian market Type-1's also had a 3 way toggle switch mounted in the base beside the terminals, which allowed the railway to select between 3 preset fixed volumes. The loud tone and 3 way volume switch Type 1's are most likely exclusive to Australia. For a long period of time, the term 'Type-1 Adjusted' was coined for a bell which produced a tone similar to the Type-2, but with a unique knocking percussiveness at the beginning of each ring. Recent discoveries have proved this to actually be a loud tone Type-2 variant, which has a different circuit board for more powerful output. The term 'Type-1 Adjusted' is invalid and does not exist.

### Type-2 (2000-2015)

Introduced in the year 2000, the Type-2 is easily the most popular variant produced by General Signals, and is one of, if not the most common electronic bell found in North America. The Type-2 took everything the Type-1 did right, and improved upon it. The Type-2 switched from green PVC pipe to gray, which was cheaper, rustproof screws were added by the early 2000s as well as removing the problematic screws on the cap, and the height of the bell was slightly shortened. Due to using the thinner gray PVC pipe, GS Type-2s are slightly thinner in appearance than Type-1s. The Type-2 is a step lower in pitch than the Type-1, and has a distinctly more jarring sound as it rings. Railroads were quick to adopt the Type-2, which cemented General Signals as a leader in the electronic bell market and allowing it to dominate. The lower pitch carried further, and the bells were much more reliable than earlier models. The Type-2 can be found on just about any railroad that uses electronic bells, although some railroads were more fond of other companies' bells. The Type-2 was discontinued in 2015 in favour of the Type-3.

### Type-3 (2015-Present)

The Type-3 was introduced in 2015, and is the current model produced by General Signals. The Type-3 is identical to the Type-2 in appearance, and cannot be visually distinguished from the latter. The sole difference between the Type-2 and Type-3 is the tone used, as the GS Type-3 is significantly lower in pitch compared to the Type-2. This is likely due to the lower pitched sound carrying better than higher pitched sounds. While the bell was slow to have been adopted upon its introduction, the bell is now seeing much success on railroads such as BNSF and RJ Corman's lines. It has not seen the same success as the Type-2, but this may change in the future despite heavy competition from Siemens and NEG.