CTS snowfighter or anyone that has removed snow over Donner Pass, How does this
past weekend’s storm compare to previous years that you worked for Cal Trans? It would be interesting to get the SWE of this past snow as I recall most of the time that the storms that come in from the north along the Cascade ridge it is more of a Powder just not this amount of snowfall, it seems that the Pineapple Express type that come off the pacific right up and parallel to I-80 drop the classic wet Sierra cement. 


To bring it back to the topic of Caterpillar I found this Channel with Cat 938G in South Lake Tahoe last year, might need something like that this Saturday a little north of there:) 

Donner Summit is a unique environment when it comes to snow!  There is a very long and detailed history of the area, including some very serious ordeals.
Research  - The Donner Party, The Train " City of San Francisco" (1952), and many other events past years.

Maybe this attachment will give you an idea.  This past weekend was in the neighborhood of 6 feet in 3 days!
82/83 we had over 6 feet in less than 12 hours!   I have seen another storm that dropped over 3 feet in less than 8 hours.   
Those are big storms and it takes a huge effort with lots of equipment and personnel to dig out of those storms.

Donner Summit elevation EB is 7228, WB is 7239

Most of the snow is "sierra cement", wet heavy, when run on it becomes what we call "pack" and it is very difficult to remove from the roadway.
Plows on trucks will not "cut pack", it requires a grader and blade as square as you can keep it without spilling too much off the toe of the blade. Limited by the amount of snow one is plowing and the shear power limitations of the equipment.   Donner is 6% grade in many locations.
Another issue, as you plow, (usually one lead truck to the left and the following 2 to the right, same with graders,  you lose width quickly.   Rotary Plows are necessary to maintain the width.  They are slow moving and complex pieces of equipment.  Breakdowns are common, objects from vehicles, truck tire chains, rocks, etc do not mix with rotary plows!
Truck tire chains are often cut out with oxy/acet torch on the site but may require return to the maintenace barn for further repairs.

Temperatures on the summit are relatively mild in comparrison to many areas.   East of the summit, Truckee and on east is often very cold. 
Hirshdale/Boca/Floristan can be the coldest in the continental USA at times.  
In the 12 years I served on the summit - the coldes I ever saw was -22F at Castle Peak (Boreal Ridge).   Seldom were temperatures ever 0 on the summit.

Every storm is different, as such there are many conditions out of the crews hands.   
When it is snowing hard and the wind is blowing, it is not at all uncommon to have ZERO VISABILITY.  Zero Visability is best described as a WHITE OUT!  All you see is WHITE!   Under those conditions, the highway must be shut down for public safety. The maintenance crews do not stop working, but it certainly is very dangerous work.  I-80 has a very large traffic volume and people today do not realize the danger or impact of snow, it has become just a nusiance to the travelling public who expects to tranverse the "hill" under all conditons without issues.   4 wheel drive, all wheel drive, snow tires do not replace tire chains!  Speed is an issue too.   One mishap causes huge problems and can block traffic for hours.  The majority are not properly prepared and many do not have the necessary chains and survival gear with them.  
Another problem (my personal opinion and experience) with commercial trucks.   Dual wheels on drive axles should be chained with Dual Chains.   As a twin axle tractor pulling  a twin axle trailer, the requirements were Duals, Singles on drive axles and single on one axle of the trailer.   Reasoning - if you spin a driver, with single chains, it will cut a trench under the chained tire, leaving the "slick" sitting on the snow and resulting in no "bite", you just sit and spin!   Proper loading is an issue too, put the weight on the drivers!
 Years past - Consolidated Freighways (CF)built a two axle cab over tractor with a push block on the front, locked rear axle and huge block of concrete over the axle.  They used that tractor to push and pull stuck trucks,.  Pacific Intermountain Express (PIE) also supplied personnel to operate and support CF's pusher.   Later years Roadway and others joined with their systems. 

I hope this helps explain some of the issues faced by the travelling public and helps to also illustrate what the maintenance crews face.  Under Ideal conditons with full staff and all equpment running ( no breakdowns) road closures are still often forced by multiple spin-outs, accidents, and visability.  Once an incident blocks the freeway, it can take hours to clear it out and resume opeations.    

My advice to anyone that does not have a pressing deadline to meet, stay off the highways and freeways in storms.  The Sierra storms are nothing to take lightly and can be life threatening.    Become part of the solution, not part of the problem.  You are responsible for your safety and your decisions may impact many others besides yourself.
Safe Travels.








 

          Donner Summit is a unique environment when it comes to snow!  There is a very long and detailed history of the area, including some very serious ordeals.Research  - The Donner Party, The Train " City of San Francisco" (1952), and many other events past years.Maybe this attachment will give you an idea.  This past weekend was in the neighborhood of 6 feet in 3 days!82/83 we had over 6 feet in less than 12 hours!   I have seen another storm that dropped over 3 feet in less than 8 hours.   Those are big storms and it takes a huge effort with lots of equipment and personnel to dig out of those storms.Donner Summit elevation EB is 7228, WB is 7239Most of the snow is "sierra cement", wet heavy, when run on it becomes what we call "pack" and it is very difficult to remove from the roadway.Plows on trucks will not "cut pack", it requires a grader and blade as square as you can keep it without spilling too much off the toe of the blade. Limited by the amount of snow one is plowing and the shear power limitations of the equipment.   Donner is 6% grade in many locations.Another issue, as you plow, (usually one lead truck to the left and the following 2 to the right, same with graders,  you lose width quickly.   Rotary Plows are necessary to maintain the width.  They are slow moving and complex pieces of equipment.  Breakdowns are common, objects from vehicles, truck tire chains, rocks, etc do not mix with rotary plows!Truck tire chains are often cut out with oxy/acet torch on the site but may require return to the maintenace barn for further repairs.Temperatures on the summit are relatively mild in comparrison to many areas.   East of the summit, Truckee and on east is often very cold. Hirshdale/Boca/Floristan can be the coldest in the continental USA at times.  In the 12 years I served on the summit - the coldes I ever saw was -22F at Castle Peak (Boreal Ridge).   Seldom were temperatures ever 0 on the summit.Every storm is different, as such there are many conditions out of the crews hands.   When it is snowing hard and the wind is blowing, it is not at all uncommon to have ZERO VISABILITY.  Zero Visability is best described as a WHITE OUT!  All you see is WHITE!   Under those conditions, the highway must be shut down for public safety. The maintenance crews do not stop working, but it certainly is very dangerous work.  I-80 has a very large traffic volume and people today do not realize the danger or impact of snow, it has become just a nusiance to the travelling public who expects to tranverse the "hill" under all conditons without issues.   4 wheel drive, all wheel drive, snow tires do not replace tire chains!  Speed is an issue too.   One mishap causes huge problems and can block traffic for hours.  The majority are not properly prepared and many do not have the necessary chains and survival gear with them.  Another problem (my personal opinion and experience) with commercial trucks.   Dual wheels on drive axles should be chained with Dual Chains.   As a twin axle tractor pulling  a twin axle trailer, the requirements were Duals, Singles on drive axles and single on one axle of the trailer.   Reasoning - if you spin a driver, with single chains, it will cut a trench under the chained tire, leaving the "slick" sitting on the snow and resulting in no "bite", you just sit and spin!   Proper loading is an issue too, put the weight on the drivers! Years past - Consolidated Freighways (CF)built a two axle cab over tractor with a push block on the front, locked rear axle and huge block of concrete over the axle.  They used that tractor to push and pull stuck trucks,.  Pacific Intermountain Express (PIE) also supplied personnel to operate and support CF's pusher.   Later years Roadway and others joined with their systems. I hope this helps explain some of the issues faced by the travelling public and helps to also illustrate what the maintenance crews face.  Under Ideal conditons with full staff and all equpment running ( no breakdowns) road closures are still often forced by multiple spin-outs, accidents, and visability.  Once an incident blocks the freeway, it can take hours to clear it out and resume opeations.    My advice to anyone that does not have a pressing deadline to meet, stay off the highways and freeways in storms.  The Sierra storms are nothing to take lightly and can be life threatening.    Become part of the solution, not part of the problem.  You are responsible for your safety and your decisions may impact many others besides yourself.Safe Travels. 

Thanks CTS, now take a breath and let your BP lower! Very informative. Good question by CR!