Clearing Two Lanes at Once - TowPLows for Soldotna and Juneau

The Alaska Department of Transportation sent out a press release saying they're going to experiment with a tow plow that clears two lanes at once.   Here's a screen shot from a YouTube video of one of these machines in Pennsylvania.  

Screen Shot from Pennsylvania TowPLow YouTube video

The description (definitely promoting these) on the video says:

This is a video of the innovative TowPlow being used on Pennsylvania highways. Invented in Missouri and widely used there, the TowPlow is a steerable trailer equipped with a snow plow moldboard and cutting edge that allows the snow plow truck driver to plow a much wider path than could be done with the truck alone.

The DOT release says they're going to test them in the two locations to see how they work and they should allow other trucks to go clear other roads sooner.  One of the video commenters thought in Pennsylvania they'd use them to cut jobs.

An evaluation of the tow plow testing on three Ohio roads (pdf) in 2010-2011 did not mention costs or savings, but listed these performance benefits and concerns:

 Benefits
Incorporating the TowPLow into Ashtabula County’s snow and ice operations proved to be a valuable addition to their snow and ice removal fleet. The County discovered several aspects of their operations that significantly benefitted from utilizing TowPLow.

• Increases the overall level of service provided to the travelling public •    Provides safer road conditions 

• Plows and treats more lanes faster and more efficiently 

• Maintains favorable pavement conditions longe 

• Limits snow and ice from bonding to the pavement 

• Frees trucks to plow and treat areas of need – ramps, shoulders, other routes, etc. 

• Completes snow and ice operations faster – less fuel, labor, and material 

• Requires less cleanup after the storm •    Decreases equipment maintenance 

Concerns  -Ashtabula County identified the following concerns regarding the implementation of the TowPLow into their snow and ice operations

• Impeding traffic flow – most importantly emergency vehicles 

• Striking obstacles on the shoulder not visible in white-out conditions (e.g., stranded vehicles) 

• Visibility of the TowPLow in blowing snow – especially snow thrown from the front plow 

• Breaking down of the tow vehicle effectively downs two trucks unless another truck is capable of towing the plow

Image from Ohio Report on TowPlow testing

The study also recommended some improvements before purchasing the equipment:

Prior to purchasing the TowPLow, several improvements to both the TowPLow and tow vehicle should be considered. Although not necessary to achieve positive results, these advancements will simplify operation for the drivers, ensure the system is utilized to its maximum extent, and help to alleviate some of the concerns.

TowPLow improvements

• Include a polytank for pre-wetting salt  

• Add a laser alignment system to define the edge of the plow 

• Position a camera at the rear of the TowPLow to view traffic behind the unit 

• Install a hub odometer on the trailer wheel for tracking the TowPLow’s usage

Tow vehicle improvements

• Purchase a truck with added horsepower and torque to increase towing performance 

• Move the material spreader under the truck frame behind the cab to enhance material application coverage (current application is altered by the trailer tongue) 

• Clearly identify the hydraulic lines for easier trailer connection

A North Dakota study (pdf) is much more succinct and does include some cost analysis:

Summary
The initial cost of the TowPLow is $74,389 with a 17 year expected life. The Bismarck District estimated the labor and equipment cost (not including the fuel) for the regular snow removal operation is $1,754 per snow event. They estimate the TowPLow operation labor and equipment cost was $782 per snow event. This results in a savings of $972 per snow event when using the TowPLow. Using the TowPLow in the snow removal operation frees up three snow plow trucks to address other major routes to better meet service levels for the public. These costs are unique to Bismarck. Although different urban and rural roadways may require different equipment and labor hours than the Bismarck section, it appears the TowPLow operation does offer a cost savings to the regular snow removal operation.
Generally speaking, the Bismarck and Fargo District comments indicate that the TowPLow is more efficient in clearing snow, and maybe safer for the employee and the public (in terms of reduced snow fog)..

I tend to be skeptical of in-house evaluations. By the time the organization gets far enough along to test the equip for several months, there is often a bias to buy the glitzy new stuff, unless it does really terribly. The bias may well not even be conscious.  But little things point to it.  For instance in this Pennsylvania study, which looks more like a promotional pamphlet than an evaluation, there is a "What are the Benefits" section, but no "Costs" section.  Instead, there's a section called "Points to Consider."  Subtle, but significant. 


From a Pennsylvania study:

What Are the Benefits?
In addition to reductions in equipment use and personnel time, savings and benefits include:

• The added weight of the Tow Plow increases truck fuel consumptionby about 10-15%; however, compared to using two trucks to do the same job, this is actually a fuel savings of 85-90%. 

• The Tow Plow can be used in a plow train, in place of a truck thatcould be deployed on a different route, thus increasing overall level of service. 

• The Tow Plow requires standard plow and trailer maintenance — asavings compared to maintenance that a second truck and plow requires. 

• The Tow Plow can be used strictly for spreading/antiskid applicationswhen plowing is not necessary. 

• During non-winter months, the Tow Plow can be used as a water tank.

Points to Consider
Here are points to consider when making a Tow Plow investment decision:   

• The cost of a Tow Plow purchased through PennDOT’s DGS Plow Contract is $73,790. 

• Required truck modifications costing $15,500 include a rear hitch module, hydraulic upgrade, and two in-cab controls; no engine or transmission changes are necessary. 

• If the tow vehicle goes down for maintenance, then the Tow Plow is out of service unless another truck with the required modifications is available. 

• The Tow Plow can be configured for anti-icing at a cost of $25,820, or with an 8 cubic yard granular material hopper at a cost of $18,184. n    Operators require overview and familiarization training, provided by the vendor. 

• The Tow Plow should probably not be deployed in urban areas during periods of high traffic volume.

 A Maine report put the costs of fitting the truck much lower:

Fleet Services, Bureau of Maintenance and Operations retrofitted a 2009 Volvo Wheeler to accommodate the towing of the plow. Changes to the truck were relatively minimal and included installation of a 45 ton pintel hook and the installation of hydraulic hoses from the trucks wing tower to the tongue of the Tow Plow trailer. Hydraulic fluid from the wing up/down function operated the lifting and lowering motion of the tow plow and fluid from the D/A slide operated the two steering axles of the trailer. These axles articulate to a maximum (see Photos 1 and 2). The standard wing is not needed when using the Tow Plow. The 8 yard hopper mounted on the tow trailer was operated by utilizing the trucks existing spreader controls.

The retrofit of the truck took about 2 days to complete at a cost of approximately $1,000 including materials.

That's considerably less that the $15,000 costs Pennsylvania reported.

Ohio says the modifications of their truck was about $5000.


 An ADN story says the Alaska plows cost $90,000 each, which puts them about $16,000 more than Pennsylvania and North Dakota paid for theirs.  But the story said the figure included shipping and installation.  What does installation mean here?  Does that include the modification of the trucks that tow them?  If not, then $16,000 for shipping seems a bit steep.

Totem lists the cost to ship a 24 foot* truck to Anchorage from Seattle at $4,036.40.  That leaves $12,000 to get it to Seattle from the manufacturer.  And given the Alaska State Ferry, a part of the Alaska Department of Transportation, goes from Bellingham to Juneau, you'd think they could work out something much cheaper, given the ferry isn't that crowded in the winter.  

*Since the total clearing path of a regular plow truck pulling a TowPlow can reach up to 24 feet, I don't think the plow could be longer than 24 feet.

LENGTH	PER FOOT RATE	OCEAN FREIGHT RATE	ESTIMATED OCEAN FUEL SURCHARGE 32.5%*	PORT CHARGE	ESTIMATED TOTAL PER VEHICLE,US$
24	$123.00	$2,952.00	$959.40	$125.00	$4,036.40

The ADN story also says the

"The one on the Kenai Peninsula will be used in the urban areas like Soldotna and Kenai as well as wider sections of area highways from Sterling to Kalifornsky Beach Road"

But the Pennsylvania study concluded:

The Tow Plow should probably not be deployed in urban areas during periods of high traffic volume.

 But then 'urban' is a relative term and Soldotna and Kenai probably wouldn't qualify by Pennsylvania standards.

Read more here: http://www.adn.com/2013/02/15/2791319/soldotna-area-sees-first-use-of.html#storylink=cpy