Harmon Industries: How a Missouri Radio Shop Built American Signal Equipment

If you have worked a coded track circuit, a constant warning time crossing, or a cab signal unit on this continent, there is a fair chance some of it was designed in a small town east of Kansas City. Harmon Industries never had the name recognition of Union Switch & Signal or General Railway Signal, but by the time General Electric bought it in 2000 it was a full-line signal supplier with about $300 million in sales, and several of its product lines are still sold today, from the same plant, under a third owner.

This is the company's history as the public record tells it: SEC filings, regulatory records, contemporary press, and the company's own words. Where those sources disagree, I say which one I trust and why. It is a companion to How the UltraCab II Works, which covers one of Harmon's best-known products from the inside.

Tap to enlarge Harmon's own era is the long blue band. The product lines kept going after the name did.

A radio man and an upholstery shop

Robert C. "Bob" Harmon learned radio in the Marine Corps and spent the war as chief sales engineer at Aireon Manufacturing in Kansas City, Kansas, a military electronics supplier that had tried, without much success, to sell two-way radio to railroads. In September 1946 he went into business for himself, as Harmon Electronics, working out of an upholstery shop in Independence, Missouri. His stated aim was to provide work for himself and the skilled people the end of the war had left unemployed, and his railroad contacts from Aireon were the obvious market.¹ The firm made no profit for its first two years.

The company's own later account says it "was created to manufacture and design train communications equipment," with a side line in the late 1940s of low-frequency inductive broadcasting systems for college campuses.² The first railroad product the record describes is a hotbox data relay: it carried alarms from trackside hotbox detectors, which sense overheated axle bearings, to a central office over existing power or telephone circuits, and the office radioed the crew.¹

A Southern Railway hotbox contract paid for the company's first real building. In 1958 Harmon left a leased building on Truman Road for its own building on farmland next to the family home in Grain Valley. The same year it began replacing vacuum tubes with transistors, and Bob Harmon later called 1958 "a turning point in the business."³ For about two decades, though, it remained what Gene Harmon later described as a custom engineering firm: around two dozen workers and under $1 million a year.¹

The business was incorporated as Harmon Electronics, Inc. in 1961, with Bob as president, his son Robert E. "Gene" Harmon as vice-president, and his wife Mildred as secretary-treasurer.¹ That is why you will see the company dated to both 1946 and 1961. Both are right: 1946 is when the business started, 1961 is when the corporation was formed.

The crossing switch that made the company

The product that turned a custom shop into a manufacturer came from the son. Crossing gates of the day could not rise until a departing train was 100 feet or more down the track. Gene Harmon's electronic switch let them rise once the train had cleared by about two feet. "By 1964 the company had a major product to sell."¹ Crossing equipment stayed the core of the business for decades: in 1988 gate switches still brought in about $20 million of nearly $65 million in sales.

That switch was the start of a line of crossing motion detectors and, later, predictors. A 1973 "digital motion detector" patent by Forrest Ballinger and Robert Heggestad is an early marker.⁴ By the 1990s the line was led by the Phase Motion Detector (PMD) and the Harmon Railroad Crossing Processor (HXP), which in the company's words "uses microprocessors to calculate the train's speed and distance to the crossing and provides a consistent warning time."⁵ Constant warning time, in other words, the job a modern crossing predictor does.

Bob Harmon stepped out of management in 1969, keeping most of the stock. "I was primarily an engineer, not a manager," he said.¹ Gene became president that November and chairman of the board in February 1975, a post he still held when the company was sold 25 years later.⁵ In 1972 Gene took the company public over the counter. The main Grain Valley plant on South Dillingham Road was operating by 1973.⁶

The Swedish years and Electro Code

In 1977 the Swedish Sonesson group bought 51% of the company through its brake and rail unit SAB, and the company traded as SAB Harmon Industries. Under that ownership it grew by acquisition. In 1981 it bought General Electric's hotbox detector line, which its own West Coast operation had been reselling. In 1984 it bought Electro Pneumatic Corporation of Riverside, California.¹

Electro Pneumatic brought Electro Code, the coded track circuit that sends "coded electrical impulses using the rails for transmission" between signal locations, replacing pole lines and a good many relays.⁵ By 1996 Harmon could say that "thousands of miles of pole line have been replaced with Electro Code."⁷ The line outlived the company by a long way: Electro Code 5 was Harmon's main development project in its last two years,⁸ and Alstom put Electro Code 6 into revenue service in 2023.⁹

In June 1985 Harmon bought back SAB's 51% stake, about 2.5 million shares, for roughly $21.8 million. Annual sales were then about $50 million.¹⁰ In 1987 Harmon Industries, Inc. became the holding company over the operating businesses.¹ Bjorn Olsson, who had run SAB's NIFE unit in Sweden, joined Harmon's board in 1986, became president in 1990 and chief executive in 1995, and ran the company through the sale, with Gene Harmon as chairman.⁵

Chase, Maryland, and the Ultra Cab

On January 4, 1987, a Conrail locomotive consist ran a stop signal at Chase, Maryland, and was struck by an Amtrak train, killing 16 people. The regulatory response included requiring automatic train control on locomotives operating on the Northeast Corridor. Harmon's own account of what happened next is short: Conrail "solicited bids," and "Harmon won this bid and completed development of Ultra Cab."¹¹

Harmon described the system as communicating "speed commands directly to moving locomotives through electrical currents in the rails," showing them to the engineer with colored lights in the cab, and applying the brakes automatically if the engineer failed to stay within the limit.⁵ A first-hand account from someone involved in the program recalls six prototype speed limiters running on Conrail SD40-2s by October 1987, and Conrail buying them at less than half the price of the competing system.¹² That is a first-hand recollection, not a company record, but it fits the filings.

Ultra Cab II is already in Harmon's annual report for 1994, which lists "carborne equipment (Ultra Cab and Ultra Cab II)" and credits that year's growth in train control sales to "the HLC, VHLC and Ultra Cab II."⁵ (KB Signaling dates its transit launch to 1992.¹³) By the 1996 report Harmon was claiming that Ultra Cab II, "combined with a unique patented antenna," was "the only such product that can operate successfully in the face of intense electrical interference generated by new, high-power AC traction locomotives."⁷ That is a company claim, but the problem it describes was real: AC traction motors put a great deal of noise into the band a cab signal receiver listens to. Two Harmon patents filed in 1995 use cancelling pickup coils for exactly this reason, and the antenna is probably one of them, though no source says which.¹⁴

The 1997 report called Ultra Cab II "a microprocessor-based train control unit" and "a key component of our Incremental Train Control System,"¹⁵ which is the next part of the story.

ITCS, transit, and going beyond the rails

Harmon's research list for 1994 already describes a "communication-based" system using onboard position tracking and data radio for movement authorities.⁵ Heggestad and Schaefer filed the patent for an "incremental train control system" that August.¹⁶ By 1995 ITCS was being installed on Amtrak's line in southern Michigan under an FRA grant. A first segment was demonstrated in October 1996,⁷ and by 1999 Harmon described a 70-mile installation using GPS for trains running "in excess of 100 mph."⁸ When FRA type-approved ITCS for Amtrak in 2012, it described the onboard computer as "an enhanced version of the GE UltraCab II."¹⁷

The same years took Harmon into transit. St. Louis MetroLink opened in July 1993 with Harmon signaling. After a speeding New York City subway train derailed in 1991, Harmon built a computer-based speed enforcement system for the subway as a subcontractor. Its first job as prime contractor was the Chicago Transit Authority's Green Line, worth more than $13 million.⁵¹¹ In December 1997 Harmon licensed Hughes's advanced automatic train control technology, and in February 1998 it won a contract of about $45 million to apply it on BART.¹⁸

Buying its way to full line

The financial record from Harmon's filings shows a steady climb with one bad year.

Year	Net sales	Net earnings	Full-time employees
1987	$57.1M	$1.7M
1990	$72.7M	($9.2M)
1994	$119.7M	$7.6M	985
1996	$175.4M	$9.3M	1,202
1998	$265.2M	$13.4M	1,662
1999	$304.4M	$0.8M	2,079

From Harmon's 10-K filings for 1994, 1997 and 1999.¹⁵⁸ The 1990 loss came from discontinued businesses, mainly a railroad tie venture.

Much of the growth after 1994 was bought. Harmon's 1998 report counted "11 companies in the past five years." The list included Servo's railroad division (hot bearing, hot wheel and dragging equipment detectors) in 1994, Vaughan Systems of England in 1996, Harmon's first manufacturing outside the US, the rest of its Canadian distributor Vale-Harmon in 1997, transit communications and Mexican and Australian units in 1998, and in 1999 the Syseca dispatch business and majority control of Italy's Siliani, which Harmon called "the largest independent signal supplier in Italy."⁷¹⁸⁸ Two unnamed customers dominated sales throughout; in 1996 the larger of them took $77 million, about 44% of the total.⁷

The spree had a cost. When freight orders fell in 1999, Harmon closed its Riverside and Long Island plants, cut about 200 jobs and took a $9.1 million charge, and net earnings dropped to $0.8 million.⁸

GE, and three owners since

GE first proposed buying Harmon in June 1999 at $28.50 a share. Talks broke off that November. In 2000 another, unnamed industrial company approached Harmon with a lower price, and GE came back at $30 a share in GE stock, a 127% premium over the previous close and above anything Harmon stock had ever traded at.¹⁹ The deal, valued at about $425 million including debt, was announced on July 17, 2000.²⁰ Shareholders tendered 93% of the stock, the merger closed on August 31, and GE announced completion on September 1, 2000.²¹

GE combined Harmon with GE Harris Railway Electronics, its 1995 joint venture with Harris Corporation, as GE Harris Harmon Railway Technology.²¹ Harris sold its share to GE in 2001,²² and by 2002 the business was called GE Transportation Systems Global Signaling. GE sold its signaling business to Alstom in November 2015.²³ Alstom in turn sold its North American conventional signaling business to Knorr-Bremse, which completed the purchase on September 2, 2024, and the business became KB Signaling.²⁴

Through all of that, the Grain Valley plant kept working. Missouri's environmental permit for 2712 South Dillingham Road lists the site's holders in order: Harmon Industries, GE Harris Harmon Railway Technologies, GETS Global Signaling, Alstom Signaling Operations, and KB Signaling.⁶ KB Signaling is headquartered there, names Bob Harmon and the 1946 founding in its own history, and still sells Ultra Cab II, Electro Code and ITCS.¹³

Bob Harmon died on March 2, 2008, at 95.²⁵

What Harmon left behind

Read as a whole, Harmon's history is a series of answers to specific problems. Crossing gates that stayed down too long got the 1964 switch, and then constant warning time. Pole lines between signals got Electro Code. The Chase collision and Conrail's cab signal requirement got Ultra Cab. AC traction noise got Ultra Cab II's cancelling pickups. FRA's high-speed corridor program got ITCS. Each time, railroads standardized on the answer, and that installed base, not the late acquisitions, is most likely what GE paid a 127% premium for.

It is also why the product names outlived the company. A quarter century and three owners after the sale, crews still run on Ultra Cab II, signal maintainers still troubleshoot Electro Code, and the work still comes out of the same address in Grain Valley.

Footnotes

1. "Harmon Industries, Inc. History", International Directory of Company Histories, Vol. 25 (St. James Press, 1999), reprinted by FundingUniverse. A secondary source, used here for the early years that predate the SEC record. FundingUniverse ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

2. Harmon Industries Circuit Board Division, "Who we are" page, harmonind.com, archived February 1, 1998. Wayback Machine ↩

3. "Looking back: Bob Harmon", Grain Valley News, 2019. Grain Valley News ↩

4. US Patent 3,838,270, "Digital motion detector", Ballinger and Heggestad. Google Patents ↩

5. Harmon Industries, Form 10-K for fiscal 1994, filed March 1995. Product descriptions, Ultra Cab and Ultra Cab II, officer table, transit projects. SEC EDGAR ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

6. Missouri Department of Natural Resources, hazardous waste facility record for 2712 S. Dillingham Road, Grain Valley (MOD000298398). Missouri DNR ↩ ↩²

7. Harmon Industries, Form 10-K for fiscal 1996, filed March 31, 1997. Electro Code, Ultra Cab II and the patented antenna, Vaughan Systems, customer concentration, ITCS demonstration. SEC EDGAR ↩ ↩² ↩³ ↩⁴ ↩⁵

8. Harmon Industries, Form 10-K for fiscal 1999. Financial table 1989 to 1999, Electro Code 5, ITCS, 1999 acquisitions and restructuring. SEC EDGAR ↩ ↩² ↩³ ↩⁴ ↩⁵

9. "Alstom launches EC6, outlines future plans", Metro Magazine, July 26, 2023. Metro Magazine ↩

10. "SAB Harmon Industries Inc. said Tuesday it has redeemed...", UPI, June 19, 1985. UPI Archives ↩

11. Harmon Industries, Form 10-K for fiscal 1995, filed April 1, 1996. Ultra Cab origin after the 1987 Northeast Corridor accident; ITCS in Michigan. SEC EDGAR ↩ ↩²

12. "War Stories Episode 29: Sadder But Wiser", Blerf Blog, September 2014. A personal recollection. Blerf Blog ↩

13. KB Signaling, "KB Signaling History". KB Signaling. Current Ultra Cab II literature: brochure KBS0143 ↩ ↩²

14. US Patent 5,586,736, "Cab signal sensor with noise suppression", Mollet, Harmon Industries, issued 1996 (Google Patents), and US Patent 5,628,478, McConnel and Johnson, filed January 1995 (Google Patents). Neither names Ultra Cab; the link is an inference. ↩

15. Harmon Industries, Form 10-K for fiscal 1997. Ultra Cab II as the ITCS onboard unit; eleven-year financial table. SEC EDGAR ↩ ↩²

16. US Patent 5,533,695, "Incremental train control system", Heggestad and Schaefer, filed August 1994. Google Patents ↩

17. FRA, "Type Approval (FRA-TA-2012-001) and System Certification for Amtrak's Incremental Train Control System", December 27, 2012. regulations.gov, FRA-2010-0029-0072 ↩

18. Harmon Industries, Form 10-K for fiscal 1998. Acquisitions, the BART contract. SEC EDGAR ↩ ↩²

19. Harmon Industries, Schedule 14D-9 (recommendation to shareholders on the GE exchange offer), 2000. Background of the offer. SEC EDGAR ↩

20. "General Electric Company to Acquire Harmon Industries, Inc.", GE and Harmon joint release, July 17, 2000. SEC EDGAR ↩

21. "GE Completes Acquisition of Harmon Industries, Inc.", GE release, September 1, 2000 (SEC EDGAR); GE Schedule TO-T/A on the final tender results (SEC EDGAR). ↩ ↩²

22. Harris Corporation, Form 8-K exhibit 99, May 2001, on the sale of its interest in the GE Harris joint venture. SEC EDGAR ↩

23. "Alstom entirely refocused on rail as GE deal completed", Railway Gazette, November 2, 2015. Railway Gazette ↩

24. "Knorr-Bremse finalizes acquisition of Alstom Signaling North America", Railvolution, September 2024. Railvolution ↩

25. "Harmon Industries founder Robert Harmon passes away at 95", Progressive Railroading, March 7, 2008. Progressive Railroading ↩