Jeffrey M. Sims ● President 7001 Heritage Village Plaza ● Suite 220 ● Gainesville, VA 20155 ● 703-549-3010



### Attn: Tad Wysor December 15, 2014

The following trailer types should be excluded fr om all aerodynamic type devices in the GHG2 rulemaking, as defined in the TTMA Publications RP No. 36 Tank Trailer Nomenclature and RP No. 66 Trailer Nomenclature. (s ee definitions below)

For bulk tank trailers, a very few of these designs have had aero de vices fitted or proven out: most efforts focus on non-spec, food grade, and certain DOT-407 tanks. DOT-406 tanks (commonly gasoline tankers) are most often fitted with extensive piping ( qualifying as work performing equipment) that would preclude most aerodynamic devices. DOT-412 should not be fitted with aerodynamic devices as they might interfere with the safe opera tion of these corrosive carrying tanke rs which need routine external examination of the shell. Until the possibilitie s of aerodynamic devices on cargo tanks are better understood, these categories of trai lers should have goals set consis tent with no aerodynamic devices
fitted.

Similarly, Aero devices fitted to Platform (Flatb ed) trailers [A trailer chassis consisting of load carrying main frames and a flat loading deck without permanent sides or roof.] have had little to no track record, as the load carried predomin ates any Cd issues. These trailers should be grouped with bulk tank trailers and have goals consistent with no aerodynamic devices fitted.

For a discussion of Van-type trailers, please examine the spreadsheet that follows the definitions
below.

TRAILER, AGRICULTURAL COMMODITY: Agricultural commodity trailer means a trailer that is designed to transport bulk agricultural commodities in off-road harvesting sites and to a processing plant or st orage location, as evidenced by skeletal construction that accommodates harvest containers, a maximum length of 28 feet, and an arrangement of air control lines and reservoirs that minimizes damage in field operations.571.121

TRAILER, AUTO TRANSPORTER: The semi trailer portion of an auto transporter tr uck and trailer combinati on designed and manufactured expressly for the loading, transporta tion and unloading of automobiles.

TRAILER, CONTAINER CHASSIS: A semi trailer chassis designed especially to tr ansport one or two containers over the highway.TRAILER, DROP CENTER (DOUBLE DROP): A trailer design employing an offset or drop in the cargo deck immediately behind the supports and another immediately in front of the suspension, the purpose of wh ich is to lower the cargo deck and/or to provide the greatest height possible for cargo in the dropped area.

TRAILER, DROP FRAME: Trailer designs employing one offset or drop in the cargo deck immediately behind the supports.

TRAILER, DUMP: Trailer designed to haul bulk cargo and unload throu gh gravity discharge, either though end door(s) and tilting or bottom doors.

TRAILER, HEAVY HAULER: Heavy hauler trailer means a trailer which has one or more of the following characteristics, but which is
not a container chassis trailer: (1) Its brake lines are designed to adapt to separation or extension of the vehicle frame; or (2) Its body consists only of a platform whose primary cargo-carrying surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent ``front end structure'' as that term is used in Sec. 393.106 of this title.
571.121

TRAILER, HORIZONTAL DISCHARGE: Trailers that are used in the road construction industry to deliver asphalt and other road building materials to construction sites (``the trailers''). The trailers are designed to connect with and latch onto various paving machines (``pavers''). With their hydraulically controlled horizontal discharge systems, the trailers discharge hot mix asphalt at a controlled rate into pavers wh ich overlay the road surface with asphalt material.

TRAILER, LOWBED: A platform trailer constructed to provide minimal gr ound clearance beneath the loading deck and designed to transport heavy, often times concentrated loads with high centers of gravity.

TRAILER, LOWBED, LEVEL DECK:
A lowbed trailer with the deck level from the back of the gooseneck to the rear of the trailer.

TRAILER, OILFIELD FLOAT (OILFIELD FLATBED): A flatbed equipped with a pick-up loop at the front for a winch line and with provision in the area of the supports to allow the nose of the trailer to be lowered to the ground for loading or unloading. Oilfield floats are normally equipped with a ro lling tailpipe across the rear.

TRAILER, POLE: Pole trailer means a motor vehicle without motive power designed to be drawn by another motor vehicle and attached to the towing vehicle by means of a reach or pole, or by being boomed or otherwise secured to the towing vehicle, for transporting long or irregularly shap ed loads such as poles, pip es, or structural members capable generally of sustaining themselves as beams between the supporting connections. 571.3TRAILER, STRADDLE: Straddle trailer means a trailer that is designed to transport bulk agricu ltural commodities from the harvesting location as evidenced by a framework that is driven over the cargo and lifting arms that suspend the cargo for transit. 571.121

TANK, DOT 406: Tank built after August 31, 1995 must comply with U.S. DOT specification DOT 406 as defined in 49 Code of Federal Regulations 178.346. Th is tank is typically used to carry gasoline, fuel oil, alcohol, or other liquid flammables. This tank is typically constr ucted of aluminum and de signed with an elliptical straight or double cross section.

TANK, DOT 407: Tank built after August 31, 1995 must comply with U.S. DOT specification DOT 407 as defined in 49 Code of Federal Regulati ons 178.347. This tank is typically used to carry solvents, plasticizers, casing head, gas, etc. This tank is typically constructed of stainless steel or aluminum and designed for pressure of at least 25 psig.

TANK, DOT 412: Tank built after August 31, 1995 must comply with U.S. DOT specifications DOT 412 as defined in 49 Code of Federal Regulations 178.348. Th is tank is typically used to carry corrosives. This tank is typically constructed of stainless steel or carbon steel and designed for a pressure of 35 psig.

TANK, DRY BULK: A tank typically constructed of al uminum or carbon steel to carry dry bulk commodities such as cement, fertilizer, sand, plastics, grain, etc. with typical densities ranging from 18 to 125 pounds per cubic foot. This tank is typically designed for an unloading pressure of 15 psig.

TANK, FRAC: A portable storage tank used to hold flushing or fracing fluid at an oil well site. Characterized by a large rectangular cross section, a single axle suspension, no landing gear, and a front winching bar.

TANK, HOT PRODUCTS: A tank typically insulated to handle asphalt and other products at a temperature over 300°F. This tank is typically constructed of aluminum, steel, or stainless steel and designed for atmospheric pressure.

TANK, MC 331: Tank meeting U.S. DOT Specification MC 331 as defined in 49 Code of Federal Regulations 178.337. This tank is typically used to carry anhydrous ammonia, propane, or other liquefied or pressurized gases. This tank is typically constructed of qu enched and tempered or carbon steel and designed for a pressure of 265 psig.

TANK, MC 338: Tank built after October 1, 1984, meeting U.S. DOT Specification MC 338 as defined in 49 Code of Federal Regulations 178.338. This tank is insulated and designed to carry cryogenic liquids.TANK, NON-SPEC: A tank not meeting one of the U.S. DOT Specifications.

TANK, SANITARY: A tank typically insulated to carry milk, vinegar, vege table oils, syrups, and othe r food products. This tank is typically constructed of stainless steel and designed for atmospheric pressure.

TANK, SELF SUPPORTING: A tank trailer whose shell is the structural support member for the vehicle.

TANK, TOFC: A tank meeting Association of American Railroads Specification M-931, Appendix F. This tank is a MC 307, MC 312, DOT 407, DOT 412 or IMCO Type 4 ta nk constructed of steel with a minimum design pressure of 35 psig. This tank trailer is for trailers on railroad flat car service.

TANK, VACUUM: Tank equipped with a pump to reduce the pressure in th e tank to much less than atmospheric pressure. This reduced pressure or "vacuum" is used for loading the tank. (See Tank, Waste). Also See 49 CFR 178.345- 1(c).

TANK, VARIABLE SPECIFICATION: A cargo tank that may be physically altered to confor m to another cargo tank specification must have the required physical alterations to convert from one speci fication to another clearly indicated on the variable specification plate. (49 CFR 178.345-1(c))

TANK, WASTE: Tank designed to transport waste consisting of liqui d and/or solids. Tank may have a full opening rear head. Tank may be equipped for vacuum loading.VansAero Reqd? Enhanced Aero Reqd? LRR Tires Required? ATIS Reqd? Style Length SuspensionYes Maybe Eventually Yes Yes Straight Floored 53' length or longer Closed TandemMaybe Eventually Maybe Eventually MaybeEventually Yes Spread TandemNo No No No Multi AxleNo No Yes Yes Other length Closed TandemNo No Maybe Eventually Yes Spread TandemNo No No No Multi AxleNo No Yes Yes Drop Deck 53' length or longer Closed TandemNo No Maybe Eventually Yes Spread TandemNo No No No Multi AxleNo No ? ? WheelboxNo No Yes Yes Other length Closed TandemNo No Maybe Eventually Yes Spread TandemNo No No No Multi AxleNo No ? ? WheelboxYes No Yes Yes LongCombinationVehicle (w/Pintle Hook)53' length Closed TandemMaybe Eventually No Maybe Eventually Yes Spread TandemYes No Yes Yes 48' length Closed TandemMaybe Eventually No Maybe Eventually Yes Spread TandemYes unless other exclusions apply No Maybe Eventually Yes 33' length Single AxleYes unless other exclusions apply No Maybe Eventually Yes 28' length Single AxleYes unless other exclusions apply No Maybe Eventually Yes Other length Single AxleYes unless other exclusions apply No Maybe Eventually ? (less thasn XX ft) More than 1 axleExclusionsVans or reefers with work performing devices under the belly (aero exclusions) (e.g. Side doors under belly mounted steps)Rear lift gates or rail lifts excluded as short distance haulersPintle hooks excluded from enhanced aeroExterior post/roof bow trailers by necessity (refuse,chip hauler etc.) excluded for off road/aero/tiresTOFC trailersLivestock Trailers with perforated sidesTrailers intended for storage/office useRollup rear doors excluded for enhanced aeroReefer units/nose & rear vents may preclude enhanced aero.Off road or vocational