Tag Archives: tanana river

Mears Memorial Bridge

The Mears Memorial Bridge was completed on 27 February 1923. The 700 foot long truss bridge spans the Tanana River at Nenana, Alaska. The bridge was the final link in the Alaska Railroad.

The bridge is named after Colonel Frederick Mears, the chief engineer and chairman of the Alaska Engineering Commission, the builder of the railroad and its original operator. In 1923, the Mears Bridge was the longest truss span in the United States and its territories. It spans the longest distance of any bridge in Alaska, and is still the third longest simple truss bridge in the U.S..


February Ice Count


The Nenana Ice Classic tripod, circa 1925

The monthly ice thickness check on the Tanana River took place recently for the month of February. I find this fascinating, so don’t be surprised if I post the March report too.

For most years, the ice thickness can run around 40 inches in February. Even after a week of -30F weather, and lows in the -44F range, there was no change in ice thickness from January. The Tanana River still has 16 inches of ice above the flowing water.

The earliest date on record for the ice to go out on the Tanana is April 20, which happened twice: 1940 & 1998. It certainly looks like that record could be on thin ice.


Behind the Ice Classic

I received a request for more behind the ice information regarding the Classic.


The Nenana Ice Classic Tripod on the Tanana River

In 1906, six gentlemen bet on the date the ice would go out on the Tanana River. The contest returned in 1917, when railroad engineers bet $801 on the date. The contest has been held every year since then, and has become an Alaskan tradition.

The tripod, is technically a quad pod. It’s made out of local logs and weighs several hundred pounds. A trough is dug in the ice for the tripod base to sit in, then a hole is bored through to allow river water to fill the trough and freeze the base in place.

Now things get really cool, but keep in mind the system was designed by railroad engineers in the early 1900’s.


The Ice Classic cleaver

A cable is fastened to the tripod, and four ropes run from the cable to a tower on the shoreline. The main rope runs through a pulley system that connects to a barrel weighted with several hundred pounds of rocks at the base of the tower. When the ice starts to move, this rope takes all of the stress and lifts the barrel of rocks several feet into the air.

A second rope has a foot of slack. This one triggers a siren in the town of Nenana to signal that the ice has started to move.

The third rope runs to a cleaver. This one has a bit more slack. The cleaver has been weighted, and also has over the years gained the nickname “Eldridge”. Named after the one time Black Panther leader, Eldridge Cleaver. However, Fred Mueller of Nenana, who designed this elegant system way back in the day, said he received his inspiration for the cleaver from the guillotine.*

When the tripod moves 100 feet, the rope to “Eldridge” pulls a pin, the cleaver is released, cutting the main rope. The counterweight crashes to the ground, and the tripod is free to float down the river.


The Official Ice Classic Chronometer

Once the main rope is cut, it falls pulling the final line, which is attached to a copper wire on the clock. The clock is then tripped, after the tripod moves 100 feet downstream, signifying the winning time.

There are actually two mechanical clocks. The one pictured here, which is a ship’s chronometer, was manufactured by the Elgin National Watch Company – which stopped making clocks in 1967 – needs to be wound once a day. The second, back up clock, needs to be wound only once every eight days.


A closeup of “Eldridge”

Photos and *behind the scenes credit: Dermot Cole/ADN, as well as other local sources


2019 Ice Classic


1st Place Winner: Nenana Ice Classic Poster, from Nenana

Tickets are now on sale for the 2019 Nenana Ice Classic. Buy a ticket, guess the date & time the ice will go out on the Tanana River, moving the iconic tripod, and win Alaska Glory, along with a dollar or two. Last year’s jackpot was $225,000.

Please note, all times must be Alaska Standard Time; tickets are on sale throughout Alaska through April 5th. Participants Outside must contact the Nenana Ice Classic directly for purchase.

Last year I was exactly three hours late with my guess. You’d think the damn Tanana could have held on for three hours!

Happy guessing!


Thin ice on the Tanana


2nd Place Winner from Wasilla, for the Ice Classic poster contest

Nenana Ice Classic officials announced the ice thickness of the Tanana River recently. It was the thinnest ice ever recorded on the Tanana in January. To be fair, the Nenana Ice Classic contest may be over 100 years old, but officials only started announcing the ice thickness back in 1989.

January ice thickness usually falls between 30 and 45 inches in January. In 2019, the thickness was only 16 inches. The previous low was 21.5″ in 2004.

The Tanana River froze over in October, which is normal, but we had such a mild first half of the winter, that the ice has not thickened to normal levels. That is the case for rivers throughout Interior Alaska right now. River travel has been sketchy in spots.

The annual Nenana Ice Classic is Alaska’s longest running game of chance. Every year we guess the date & time the ice “goes out” on the Tanana River. Tickets for the 2019 event go on sale February 1.


The SS Nenana


The SS Nenana on The Yukon River

The SS Nenana is a steam powered, sternwheeler that was originally commissioned by the Alaska Railroad in 1932 for their Steamboat Service. Her parts were built in Seattle, then shipped north to Nenana, Alaska and assembled there. Named for the community where she was built, the SS Nenana first entered service in 1933.

The Nenana has five decks: cargo; passenger or saloon deck; boat deck, which housed the life boats; the Texas deck, which had cabins for the captain, crew and any VIP travelers, and topped off with the pilot house.


The SS Nenana pushing a barge

At 237′ long and 42′ wide, the Nenana had 22,000 square feet of deck space. She was built to handle passengers and freight, housing up to 50 passengers in 24 staterooms, and could haul 300 tons of cargo. A full load usually had a crew of 32 and a passenger list of 35. Completely loaded, the Nenana drew only 3’6″ of water.

From 1933 – 1954 she ran the Tanana & Yukon Rivers from May through September. Her main route was between Nenana and Marshall, which was 858 miles. The Nenana had one of the most advanced power systems of its time: twin, tandem 330 HP horizontal condensing engines. The engines could recycle 85% of the steam back into water, allowing the Nenana to be surprisingly quiet. She was powered originally by burning wood, and could store 230 cords of firewood on board. In 1948, the Nenana was converted to burn oil.

While traveling the Yukon River, the Nenana could push up to 6 barges. On the Tanana River, she was limited to only one barge, due to that river’s sharp turns.

During WWII, the Nenana was a vital part of the war effort. Between the massive military buildup within Alaska, and as aircraft and other equipment was ferried across the state on its way to Russia, the Nenana moved supplies for Galena Air Base and a host of other military outposts scattered along the Yukon River Basin.

By 1955, the SS Nenana was pushed out of the freight and passenger business by cheaper and faster means of transportation. Her story doesn’t end quite there, however.

Film footage courtesy of the University of Alaska Archives; photos courtesy of “Friends of SS Nenana”


The Nenana River


Nenana River

The 140 mile long Nenana River forms the eastern boundary of Denali National Park. This tributary of the Tanana River, is a popular white water rafting destination. The Nenana begins as a Class I, but turns into a Class IV in the Nenana Gorge.