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The secrets of good spec writing

THE main goal of a specification is to initiate a purchasing procedure that results in a piece of equipment that can perform the job it is supposed to do.

In today's highly competitive market, if the spec is not written correctly, the customer might not get equipment he wants.

“Vendors bidding on a bid are not going to quote anything more than what's in the specification, especially these days where they can lose a bid for a $50,000 truck on a hundred dollars here or there,” said Force America's Jack Fieweger, who gave a presentation at the Municipal & Truck Equipment Exposition in Chicago Aug. 28. “Even if they know something should be bid one way, if it's not in the spec, they can hardly afford to quote $200 worth of extra equipment if that's going to cost them the order.”

Fieweger said spec writers might have four sub-goals:

  • To get the best price for the equipment.

  • To minimize the amount of confusion during the bidding process by minimizing phone calls to the spec writer by confused vendors, the amount of incorrect bids, exceptions, and options quoted, and the chance that the spec writer's decision makers will accept a bid that does not meet the requirements of the job.

  • To standardize the fleet by buying equipment with a proven track record and is serviced locally, and that is familiar to the fleet's operators, easy for the mechanics to fix, and compatible with parts already in stock.

  • To upgrade to newer equipment that is more powerful, reliable, efficient, or easy to use; to buy from suppliers with better support services featuring stronger local product and technical support, ones that will train operators and mechanics on site; and to eliminate equipment and suppliers that have a track record of poor performance.

The keys to writing

His general spec-writing recommendations:

  • Be thorough. Specify all the equipment that will be on the truck. For example, if the desired piece of equipment is a closed loop spreader control with a reversible auger, make sure that's in the spec.

  • Be accurate and consistent. Make sure the spec doesn't contradict itself, which might happen if a fixed-blade plow is called out in one part of the spec, but a reversible plow is in another section. Don't ask for the impossible, like a manual transmission and pump continuously driven from the transmission. Care is necessary when using specific part numbers.

  • Be specific. Make sure all the desired options are called out, such as stainless steel parts and special electrical connectors, along with special installation requirements (shock mounts, adjustable controller stands.) Don't be afraid to call out specific manufacturers and parts if they meet the goal.

  • “Your decision makers will likely award the order to the lowest bidder who meets your spec,” he said. “If you are not specific about everything you want, the bidders will likely submit the cheapest products that meet your specification. If you don't want the cheapest possible equipment, make sure you specify what you do want.”

  • Enforce the spec. After time has been spent on writing a thorough, accurate spec, don't accept bids that don't meet standards. If the truck is delivered and doesn't measure up, don't accept it until it is fixed.

“We sometimes run into a situation where bids will not meet spec, and they're accepted,” he said. “Then they can end up with the same problems they'd end up with if they didn't write the spec well in the first place. You can end up with cheap equipment, and guys will just accept it. Or people higher up will accept it. They end up with breakdowns, inadequate parts, underpowered equipment, equipment that's not going to get the job done for them. And in the next round of bids, once they establish that they'll just take what people gave them, whether it meets their spec or not, then it's just a race to the bottom. The next time a bid comes out, because people realize they can quote them whatever the cheapest thing they can get their hands on and they're not going to enforce it if it doesn't meet their spec, then the quality of equipment they get really tends to spiral down.”

Alaska spec 100 pages long

Fieweger gave an example from personal experience: a bid for 30 plow trucks for the state of Alaska. The state's spec was over 100 pages long and was very specific about which parts and equipment the state wanted, and how it was to be installed. After the first truck was built, the head spec writer and two shop foremen spent a full day inspecting the truck.

“That's an example of a place that did a very thorough job of spec writing,” he said. “In the state of Alaska, they probably need to have the most reliable truck out on the market because they're plowing snow nine months a year and have drivers out on some remote stretch of highway 50 miles from anywhere. They can't afford to have their trucks breaking down or getting stuck, and getting parts is a big problem for them. So when their spec comes out, it's 100 pages. Everything that they wanted was on that spec. If they wanted a plow bolted on in a certain way, it was spelled out exactly. If they wanted stainless steel parts so that they'd hold up, it was called out everywhere.

“But even for a guy in Illinois who doesn't have quite the extreme environment as Alaska, it's pretty much the same expectations of his truck: run through storms and not break down. But that guy, in a lot of cases, has been sending out a spec for the same truck that's five pages and at best barely calls out what he's looking for, and there are parts missing that he needs. There are basics called out, maybe a hydraulic pump, but no further specifications, so he gets either a cheap product, undersized product, or underpowered product.”

A detailed sample

Fieweger gave this sample bid specification for a closed center load-sensing hydraulic system as an example of how details need to be listed:

  • Hydraulic pump (PVWH34L): The hydraulic pump shall be a US-manufactured axial piston pressure and flow compensated load-sensing type. The pump shall be cast iron construction and rated to 4.67 cubic inches per revolution at maximum stroke. The pump shall have a 2" suction line, be rated for up to 3000 rpm and pressure, have a 1" keyed drive shaft and SAE type C mounting flange, with a 1" steel ball valve at the outlet of the pump.

  • Hydraulic pump (PVWH45L): The hydraulic pump shall be a US-manufactured axial piston pressure and flow compensated load-sensing type. The pump shall be cast iron construction and rated to 6.0 cubic inches per revolution at maximum stroke. The pump shall have a 2" suction line, be rated for up to 2600 rpm and 3000 PSI, have a 1" keyed drive shaft and SAE type C mounting flange, with a 1" steel ball valve at the outlet of the pump.

  • Mounting: The hydraulic pump shall be mounted with shaft centerline parallel to the crankshaft centerline and at a level to create not more than a three-degree angle on the driveline. The pump mounting shall be incorporated with a bracket fabricated to mount in the extended frame rails of the truck.

  • Drive line: The hydraulic pump shall be driven directly off the engine crankshaft via a splined driveline to allow for movement. The driveline shall include grease fittings on both u-joints (SPICER model 1310 series).

  • Reservoir: The hydraulic reservoir shall be (20-,30-, 40-) gallon capacity and be equipped with the following: basket type filler breather cap; magnetic drain plug; 2" NPT suction with 100-mesh screen type filter; separate return port for case drain line; sight temperature gauge externally mounted; internal baffling; and 2" full flow ball valve.

  • Optional items: The hydraulic reservoir shall be equipped with an electric level or level/temperature sending unit to be wired to the dash panel and backlit for designated warning.

  • Filter (telescopic hoist, single cylinder or twin cylinder under body hoist): Hydraulic oil filter shall be mounted in the reservoir. Hydraulic filter shall be 10 micron and rated for no less than 50 GPM. Filter shall be a ZINGA model TS-1200-25-1-0 with filter condition indicator gauge.

  • Optional: A 12-volt indicator switch shall be installed in addition to the normal pressure gauge to indicate filter bypass, and shall be wired to a panel and backlit for filter bypass warning.

  • Valve controls: The valve controls shall be a Morse remote system with sealed cables, and must have bonnet-type connections at valve banks as to seal hydraulic valve spool ends. The valve controls shall be mounted at the right of and convenient to the driver. The cab controls are to be a combination of a single and dual axis levers stacked together for operation of all sections in the hydraulic valve bank. The cables shall be stainless steel capable of 100 lb of push and pull.

  • Spreader valve: To be load sensing dual flow regulator pressure compensated type. Both control knobs to have 11 detent positions. Valve to be mounted on a stand with all hoses enclosed.

  • Control valve (V20): The control valve shall be US-manufactured. The valve is to be Gresen model V20 load sending stackable spool type with O-ring ports mounted between the frame rails outside the vehicle cab. Valve sections to be arranged as follows: (1) Hoist, 4-way for a double acting cylinder with down side work port relief set at 500 PSI; (2) plow lift, 3-way for single acting cylinder with detent in the down position for float with flow control; (3) plow angle, 4-way for a double acting cylinder with flow control; (4) wing toe, 4-way for double acting cylinder with flow control; (5) wing heel, 4-way for a double acting cylinder with flow control; (6) sander, 3-way detented section with b-port blocked out.

  • Hydraulic lines and plumbing: All hydraulic lines and plumbing shall be of sufficient capacity so as to not create heat or turbulence within hydraulic system. Suction line between reservoir and pump shall be a minimum of 2" I.D. with a minimum SAE 100-R4 rating and shall be secured on both ends via heavy duty banding straps, radiator hose clamps unacceptable. All pressure hoses, including signal sense to pump, shall have swivel fittings on both ends and have a minimum SAE 100-R2 rating. Return lines and case draining shall have minimum SAE 100-R1 rating.

Hydraulic lines shall be routed to minimize interference with equipment and chassis components requiring periodic servicing. Support brackets, grommets, and tie wraps shall be provided where appropriate to protect lines from damage by abrasion, cutting, or impact.

Hoses shall not be routed near exhaust manifolds, pipes, bolts, sharp edges, and exhaust system to prevent wear, fatigue, or fire. Pipe fittings are not acceptable in any high-pressure line. Maximum distance between support clamps on all hydraulic lines shall be 24".

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