Runaway truck: 35 tons, 100 mph — and 1 miraculous ending

Posted by David Middlecamp on March 14, 2014 

This photo, published April 20, 1953, shows the runaway truck after its wild ride from the top of Cuesta Grade to San Luis Creek on Nipomo Street at Monterey Street.

W.H. SUMNER — Telegram-Tribune

According to Google Maps, the route from the top of the Cuesta Grade to the San Luis Obispo Children’s Museum at the corner of Nipomo and Monterey streets is 6.4 miles long and takes 10 minutes to travel.

Assuming you have brakes — and a modern freeway.

In 1953 a truck driver had neither luxuries, and the highway came straight into downtown.

Sumner Boyd, 26, didn’t want to be a truck driver, but there he was, perched at the head of 35 tons of careening Mack truck and freight — his brakes failed, drive train snapped and gravity accelerating the speed to an estimated 100 miles per hour.

It would take a miracle for no one to be killed or badly injured.

Today Google won’t even draw routes through Mission Plaza. So Boyd did not have to reckon with that obstacle.

He did have more than 1,200 feet of elevation to freewheel before the truck came to rest in San Luis Obispo Creek across the street from where the Children’s Museum is today.

By the way, it was foggy and dark, too.

Telegram-Tribune readers got the full 5 cents worth of news on April 2, 1953, from two front-page stories.

If anyone has a photo to share, please contact me at

Runaway truck roars through downtown SLO: Crash ends wild ride off Cuesta

The city’s downtown business district miraculously escaped disaster when a huge truck and trailer went out of control on the fog-bound Cuesta Grade and rolled through the heart of San Luis Obispo at 3:30 this morning.

Unable to turn at Nipomo Street as it roared down Monterey Street at speeds believed near the 100 mile-per-hour mark, the 35-ton vehicle and its cargo crashed through an old frame warehouse and hurtled down into the San Luis Creek bed.

Driver escapes

The driver, Sumner Boyd, 26, Los Alamos, N.M., climbed from the cab of the demolished truck with only minor scratches, staying with the stricken vehicle during the entire wild journey.

Boyd told police that his harrowing experience began when the truck started down the crest of the Cuesta grade on Highway 101.

His air brakes failed to function when first applied. Some control was retained because the vehicle was in-gear, in a “third over” position of its transmission.

As it gathered momentum down the tortuous route, Boyd said he felt the transmission line snap as the metal was twisted off by the great pressure.

The vehicle then rolled in a manner described by Boyd as “freewheeling,” with no mechanical hindrance or linkage to its many wheels.

Fog hampered vision

The pre-dawn fog which shrouded the Grade was so dense at the time of the accident that Boyd could only see a few feet ahead of him.

He said he manipulated the truck by sticking his head out of the cab for better vision.

He had no idea of the speed it attained, since at no time did he withdraw his head for a foolhardy glance at the speedometer.

As the vehicle roared into the city limits it was careening from side to side of Monterey Street, wagging its trailer like a vicious and lethal tail.

Police were awestruck by Boyd’s amazing feat in negotiating the curve where Monterey rounds Chorro Street, at the approach to the Old Mission. They pointed out that a parked car made the turn even more difficult.

Boyd said the truck lost some speed on the slight grade between the Mission corner and the (Carnegie) library but then a down slope ended his hope of halting it before a crash occurred.

Building looms up

He saw the white-painted warehouse looming before him but could recall little of the actual impact.

After the truck had taken a corner of the building with it as it plunged into the creek, Boyd had a moment of panic when he thought he was trapped in the cab.

He said he also feared fire.

He turned off the ignition, as the motor was still running wildly, and discovered a door of the cab would allow him to make his escape.

Boyd was taken to a hospital for examination but was released when it was determined he was only scratched and shaken up.

The 1951 Mack truck belonged to Harry Williams, Fort Dodge, Iowa, who is Boyd’s employer.

It was loaded with 37,000 pounds of sudan grass seed contained in burlap bags. A ton of the seed was destined for a San Luis Obispo firm.

Boyd said he picked up his cargo at Yuba City and was en route to Los Angeles after the single stop in San Luis Obispo.

Insurance adjusters were on the scene early this morning, arranging for salvage of the cargo and the difficult job of retrieving the wrecked truck and trailer.

No more trucks, driver of ‘runaway’ says

“I’ll never drive another truck!”

That was the grim pledge made this morning by Sumner Boyd, 26, the truck driver who miraculously escaped death when his huge truck went out of control as its brakes failed coming down the Cuesta grade at 3:30 a.m. today.

“When I started out this time, I told my friends this was my last trip. Now I'm certain of it.

“I’m a journeyman electrician, you see, and from now on that is the trade I am going to stick to,” he swore.

Boyd seemed none the worse for his experience when he visited the police station this morning to talk to insurance adjusters.

He was calm but said that he had been too nervous to sleep a wink at the hotel where he was taken after treatment by a physician revealed only a few minor scratches.

Boyd does not know how he avoided disaster as the big truck careened through the city. He has no idea how fast he was going.

He said there was virtually no traffic on the highway as he roared down the Grade, but he did have an added anxious moment when he had to pass another truck coming down the slope.

Boyd said that he did not believe the other driver, or those of any other few vehicles he met or passed, realized his peril.

Although he kept cool enough to maintain a firm hand on the steering wheel, his greatest fear was of the swaying trailer loaded with an 18-ton cargo, which careened dangerously and threatened to turn him over at any moment.

He was likewise unable to describe how he got around the corner where Monterey street swings past the old Mission, or of missing a parked car which provided an added hazard.

He said that he saw a white building rushing at him as he reached the dead end of Monterey street and then he felt the sensation of the truck crashing through a corner of the building and into the creek.

He said it was his first trip over the Cuesta Grade, and he reiterated that it would be his last.

“I called my boss by telephone this morning and told him of the accident. But I made him promise not to tell my wife. She would be awfully worried until I reached home,” he declared.

“You see, we are expecting our first baby in a couple of months. That’s the reason why I’ll never drive a truck again!”

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