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K-M back from the dead

By February 28, 2017Features

By Bob Zenk, Pacific Locomotive Association
Reproduced with permission from the PLA Niles Canyon Ry. Club Car

Tuesday, February 14th was Valentine’s Day. And what finer bouquet of roses could the crew of our Krauss-Maffei have asked for than the fragrant perfume of a perfectly-running Maybach MD 870 V-16 turbomotor?

After nearly a half-century of slumber, the No. 2 Maybach V-16 twin-turbocharged diesel prime mover of SP 9010 was given the start impulse. As it began to crank steadily under the Dynastarter’s urging, it hummed and ticked like a sewing machine. Six seconds later, it started issuing wisps of white smoke: the beginnings of compression ignition.

At one minute and forty seconds into the carefully-monitored cranking, with a firm nudge of the fuel rack by Tom Hambleton after a ‘go’ sign from 9010 crew chief Howard Wise, the motor suddenly coughed and bellowed, cleared its passages of soot and sleep — and settled into an unexpectedly smooth idle!

Camera at the ready, PLA’s Dexter Day caught the exact moment that SP 9010’s Maybach awoke. After coughing up a ball of soot, the motor fought its way to motion for a few more seconds, after a slumber of nearly fifty years.

As fresh, preheated coolant courses through its passages, Maybach Mercedes-Benz MD 870 Serial No. 91168 holds its exhaust butterflies open with clean gases, a bare hint of smoke, and a rock-steady idle of 680 RPM, just like the book says. Crew chief Howard P. Wise watches attentively, in this photo by Jim Evans

No hunting, no missing, no histrionics or arduous labor. The merest trace of blue smoke issued from between the distinctive KM butterfly exhaust flaps, changing to a perfectly clean stack when the fuel rack was advanced. Even the experienced crewmembers, well-used to the uncertainties of coaxing dormant diesels into motion, were hardly prepared for how smoothly and almost instantly Maybach Mercedes-Benz Motor #91168 came back to a comfy, steady state of controlled combustion. Could a motor be happy to be alive? It sure seemed so.

Diesel specialist Tom Hambleton works the fuel rack, and is a valued advisor to the SP 9010 restoration effort. With the help of many talented volunteers around the world, the sole surviving USA Krauss-Maffei has now taken a major leap towards becoming a working locomotive. Photo by Jim Evans

Mellow piston music is not something you expect from a 54-year-old, 2,000-horsepower German-made motor — especially one that hadn’t run since Lyndon Baines and Lady Bird Johnson still called the White House home. And perhaps most especially because as SP 9010 came onto the property in 2008 it hardly looked the part of a future runner. But back then, it had only just met Howard Wise and the PLA.

Careful work to bring the precision-made V-16 back online began in earnest in the summer of 2010, when the motor was broken free by hand and turned through a few hundred revolutions by Howard, assisted on prybar duty by PLA volunteers Dan Furtado, Bob Zenk and Rob Fern, the latter bringing his Maybach preservation experiences in the UK direct to Brightside. In the intervening years, Howard and crew, including PLA’s Dennis Mann, Rich Anderson, Gerry Feeney, and Bill Stimmerman — with the assistance of qualified volunteers in the USA, Germany, the UK, and Italy — have inspected the motor from the top of its twin Maybach turbos to beneath its many inspection covers, even to elevating one side of the motor off its mounts by a few inches to inspect piston rods and the huge roller crank bearings.

Howard’s lengthy pre-start task list proves you don’t attempt to start a sophisticated motor like this without intense and diligent preparations. Over the last six years, all sixteen unit fuel injectors were replaced by rebuilt units from the UK; the good folks at MTU Friedrichshafen (corporate successor to original motor builder Maybach Motorenbau) rebuilt the resilient flywheel coupling for us in concert with research and liaison work done by our German engineer advisors. The crankcase was flooded with fresh motor oil to bathe the crankshaft rollers, and WD-40 was liberally applied to each of the sixteen cylinders, well before the motor was broken free through careful but firm manual coaxing. Lube oil was run under pressure and observed to flow from bottom to top, reaching everywhere it was supposed to. Gallons of fresh coolant with corrosion inhibitors were introduced, minor leaks were corrected, and the motor was observed to hold pressure. Howard has even built from scratch a coolant water preheater; a strict requirement for starting any Maybach MD motor is that the cooling water be above 100ºF before the start switch is ever moved. We have heard many stories that SP was not always diligent about following such instructions, and these motors are built to exacting tolerances, with little tolerance for neglect, abuse, or freelancing. But Howard and crew have been following the book religiously. And this Maybach, determined by inspection to have been in supremely excellent condition when SP 9010 was retired in 1968, is now surely receiving the best and kindest treatment it’s ever known!

In the weeks and days before the motor was started, Howard and crew used the newly-rebuilt Dynastarter and freshly-installed Welte Group main Cardan driveshaft to spin the motor at cranking speed, without an intent to start. From those tests, it was clear that there were no mechanical obstacles to starting this priceless MD 870. On January 17th, preparations were complete; a first starting attempt was made with the attendance of diesel specialist Tom Hambleton and a cast of PLA’s SP 9010 regulars. SP 9010 was towed into the open, and long jumper cables were run to another PLA locomotive to boost the temporary lower-capacity batteries currently aboard SP 9010.

But there was no joy in Mudville that day. There was a hint of curling white smoke, but no fire. With an occasional ‘woof’ from deep inside, the motor seemed to want to get going, but Howard and Tom soon discovered smoke pouring from a tennis-ball-sized hole in one of the turbo exhaust elbows. The attempt was halted. And the later consensus of the team was that the cranking speed was just not quite as fast as needed, to overcome any sticking valves and rings or any lost compression due to the years of inactivity. It was a letdown, and without question a depressing day. But anyone who’s worked on a difficult project knows that there are setbacks, and also knows that with fresh effort, disappointment can be reversed. After repairing the hole in the exhaust elbow (no mean trick to extricate that awkwardly situated part) plans were made to use fatter, shorter jumper cables to increase the cranking speed — and to try again.

And on Valentine’s Day, at about 11:20AM Pacific Standard Time, Motor 91168 came to life. And PLA not only had the world’s sole surviving Krauss-Maffei ML 4000 C’C’ Series Unit — we also had the only running Maybach MD 870 motor in North America!

Howard has posted the raw video taken that day to YouTube, and it can be enjoyed here:

SP 9010’s Minister of Propaganda, Bob Zenk, has also posted edited versions to the Southern Pacific 9010 Facebook page. That posting has to date been viewed by over 65,000 SP 9010 Facebook followers, friends, and families worldwide! And the compliments keep pouring in: Go Howard, Go PLA, Go 9010! No one can quite believe it. Yet everyone held onto the faith — if it could be done, Howard and crew could do it.

Next steps are to get the engine governor operating autonomously, so the throttle in the cab can be used to advance the motor RPMs. Once that’s been accomplished, the motor is ready to provide rotational impulse to the rear Voith L 830 rU turbo-transmission for testing, so we can see how the transmission behaves under load. The Voith unit has already been rewired, replumbed where needed, refreshed with new Dexron fluid, painted, and inspected, even spun up with the Dynastarter to pre-load a torque converter and watch as pressures came up normally. In short, it seems in every way to be as nice the motor to which it’s now finally been re-connected.

The distance we’ve come is remarkable. It started with not a few skeptical eyes rolling skyward, as the rusting hulk of a former Simulator Camera Car was towed onto the property in Summer 2008. And it’s brought us to where we stand today: on the brink of making this one-of-a-kind sole survivor a self-powered operable locomotive — and using its own unique and original diesel-hydraulic components.

9010 posed before the engine revival.

It was clearly the best Valentine’s Day for SP 9010 ever. Howard, ever the master of understatement, will often remark on a good work session by reporting “It was a good day” — and there were plenty of extra adjectives added by Howard and everyone else who witnessed the sights and sounds that Tuesday!

And yet — there was one single  disappointment. Something expected which never materialized. There simply were none of the highly-anticipated, billowing clouds of jubilant Maybach smoke, obscuring visibility for a mile in either direction and alarming the Alameda County Fire Department. Nope — just a single sophisticated German high-output diesel motor, built over half a century ago, running with unbelievable steadiness and a whisper of haze at the stack, under blue Brightside skies.

And we’re okay with that.

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