Yeah...it takes an insane amount of training to get certified--and stay certified--on the kind of high-tech inspection equipment the SRS cars use. Whereas any generalist in the track dept. can get quick certifications on running a geo train and be up for an in-house inspection assignment when the Amtrak Corridor Clipper car & associated equipment makes the rounds. The SRS staffers are more like certified hospital ultrasound med techs...but with a high-level engineering degree also required because the 'patient' being examined is forged steel ribbon. To give some sense of just how rare well-qualified rail ultrasound techs are in the industry, Sperry staff actually
live onboard their signature yellow DMU's throughout a "residency". There's dormitory and kitchen space onboard, and they trade off shifts to cover as much mileage per day as possible...limited only by dispatching slots. The sperry.com website has a nice "A Day In The Life of a Sperry Driver" employee recruitment video giving a beginner's overview of what they do. They also do plenty of regular localized inspection work with hi-rail equipment using employees across the experience spectrum...but their premier doodlebug service is its own rolling laboratory and hotel room.
To scale such slow-moving inspection movements over hundreds of thousands of route miles it pretty much takes a company that can base all its operations on those "always-on" residencies to be able to perform the task with any sort of cost-effectiveness. Especially when you factor in the level of staff qualifications required, and the rapid advances in technology that get those ultrasound machines (and associated staff qualifications) upgraded to greater complexity every few years. Maybe there's one Class I colossus out there like a UP or BNSF that has the scale to somehow manage this task efficiently enough in-house, but even Amtrak and the eastern Class I's like CSX and NS contract all out to Sperry. If Sperry and its exceedingly few competitors didn't exist, this sort of necessary function would pretty much have to be federalized and absorbed straight into the FRA because of how singularly unusual and specialized it is. Probably the only reason it hasn't been federalized is because Sperry has managed to carve out 85 years worth of expertise and self-profitability providing this one
very specific service...and do it better than the FRA ever would in-house, so there's never been a reason to touch what works.
Sperry world headquarters is near the end of the Metro North Danbury Branch...midpoint between Bethel and Danbury stations:
https://goo.gl/maps/agZYybz2Qq32" onclick="window.open(this.href);return false;. Commuters to/from Danbury will see their signature yellow doodlebugs parked next to the carhouse by the Shelter Rock Rd. grade crossing, so they're a very frequent sight all across Fairfield County when they're en route at normal speed from HQ to their next eastern residency assignment. Ditto Springfield Line and the B&A whenever they're en route to Eastern MA, Greater Portland, and Northern ME. We definitely get a lot more doodlebug sightings in this part of the country being so close to their primary routes-of-origin.