Guidelines Written to Aid in Writing Specifications, Justifying Purchases
A recent National League of Cities survey of communities across the nation identified the need to improve the development of fire apparatus specifications as a top priority. Economic pressures on local governments are also creating an environment where justification of apparatus purchases on solid cost-effectiveness grounds is becoming increasingly important.
In addition to cost, specifying apparatus performance levels that are properly matched to the fire hazards and road conditions in a given community is equally important in evaluating costeffectiveness. Too frequently the lowest bid criteria is applied without proper consideration of what this means in terms of performance. Objective procedures are needed for determining fire fighting and road performance as well as other apparatus requirements that can be justified to the appropriate government body. Procedures are also needed for writing a comprehensive, clear, and technically accurate specification to communicate these requirements to manufacturers.
To satisfy these needs, a project has been in progress since 1974 to develop a procedural guide to aid fire officials in the justification, specification and purchase of pumpers and to identify areas offering improvements in performance. This project was initially sponsored by the National Science Foundation under its Research Applied to National Needs Program but in 1977 was transferred to the National Fire Prevention and Control Administration, now the United States Fire Administration. The project team consists of engineers at Mission Research Corporation in Santa Barbara, Calif., working with a 25member national advisory committee composed of fire chiefs from both metropolitan and rural fire departments, and representatives from equipment manufacturers, the Insurance Services Office, the National Fire Protection Association, and various state and federal government agencies, including the USFA and the Center for Fire Research at the National Bureau of Standards.
Guide being tested
Presently a working version of the guide has been completed and is being field tested in 11 communities nationwide. They represent a wide range of conditions with regard to geographic area, size, fire hazards, road conditions, form of government and equipment purchasing practices. These communities are presently using the guide to determine their apparatus requirements and to develop bid specifications. Any problems or difficulties they encounter will be corrected and the final tested guide will become available for distribution through the USFA late this year. For information on how to obtain a copy of the guide, phone or write to the United States Fire Administration Library, Washington, D.C. 20230, 202634-3913.
Traditionally, a fire chief tries to get a known quality and capability in apparatus by writing hundreds of design details into the bid specifications—e.g., engine power levels, rear axle ratios, etc. By specing each component by design details or by make and model, the specifications writer is writing a design specification.
Design spec failings
Although in some situations specifying components by design may be desirable, design specifications generally have the following drawbacks: restricts competition, which can also drive up costs.
- Focusing on design details without adequately considering performance and cost implications may result in overloaded, underpowered, unsafe and costly vehicles that are not properly matched to local conditions and budget restraints.
- Overlooking how all the components of the apparatus interact to achieve road and pumping performance can result in technically inconsistent or incompatible specifications and a vehicle whose performance is degraded because mismatched components are used.
- Meeting each customer’s special design results in lack of uniformity that can drive up the cost of fire apparatus.
- Writing the specs so that only one manufacturer can satisfy the bid request
Writing a design specification also requires considerable technical expertise. Many fire departments (particularly those that don’t buy apparatus often) may not be up-to-date on what new equipment is available or what a good specification should contain.
For example, during the project, over 50 bid specifications from departments all over the nation were reviewed. In general, very little similarity in organization, content, form and detail was found. Moreover, the organization of some specifications was confusing in that requirements for a given component were not grouped in one clearly identified section. Furthermore, some specifications were incomplete or unclear, and, in other cases, technically inconsistent or inaccurate. Because of this, fire apparatus manufacturers frequently find themselves interpreting specifications rather than responding to a clear statement of what is required. Misunderstandings can and do arise from ill-written specifications.
All the above problems waste money. More importantly, if apparatus performance is inadequate for local conditions, the lives of fire fighters who man the engines and the lives and property of the citizens who are protected by them may be endangered.
To get around some of the problems caused by design specifications, private industry has pioneered a method of specification that emphasizes performance. In developing a performance specification, the buyer first analyzes his operating conditions, job requirements and performance objectives. For example, in the construction industry, a construction contractor estimates the payload weight (dirt, rock, sand) that the vehicle must move within a given time while taking into account key operating conditions, such as hills, to establish an overall performance requirement for acceleration, top speed, and hill-climbing ability.
The differences between the design and performance specification procedures are important. In the example above, the construction contractor works out performance requirements based on his unique operating needs. He is the expert at this. He leaves it to the bidders to figure out what engine size, transmission, rear axle, and chassis is needed to meet these requirements. The manufacturer can use all his engineering knowhow, enterprise, and ingenuity to meet the requirements while beating the competition’s prices. This method squarely sets the responsibility on the manufacturer to make sure all the components are fully compatible and can get the job done.
Not all components of a fire pumper can be specified by performance. While the most important functions of a pumper (over-the-road response and pumping) are ideally suited to performance specification, some features at present can be specified only by design characteristics. Some reasons for this include:
- Accepted standards by which to measure or test performance are not available, e.g., cab visibility.
- Past operating or maintenance experience with a particular component or design has been favorable (or unfavorable).
- Maintenance and operating benefits of fleet standardization must be considered (e.g., standardization of spare parts).
- Matters of taste, style, or other subjective factors are involved (e.g., cab shape, trim, insignia, etc.).
The project staff recognized these limitations. The resulting specification guide stresses a performance approach, but allows design to be introduced when needed—and then with a fuller appreciation of the technical and cost implications. The resulting specification is really a hybrid, or composite, that emphasizes performance.
How guide is helpful
The guide contains a comprehensive and systematic procedure that enables a community to determine accurately its apparatus needs and to translate these needs into specific performance requirements. These performance requirements, in turn, form the basis on which to write the actual specification, and the guide provides a rational, stepby-step procedure to accomplish this. The end product is a specification which is comprehensive, technically accurate, consistent, and justifiable.
The guide itself is quite comprehensive since it must be responsive to the diverse needs of users throughout the nation. The format is flexible though and the user can concentrate on specific chapters or sections and skip others, according to his particular needs. In this regard, the guide is not meant to replace the judgment or past experience of the user. It simply provides important specification information in a systematic format to aid his decisionmaking and to help justify apparatus purchases. Even though your department may have a specification that has been used in the past, the guide may still be of use to you in one or more of the following ways:
- To check or update your road and pumping system performance requirements, particularly if the road or fire risks in your community have been changing.
- To assure that you can justify your apparatus purchase on solid cost-effective grounds.
- To assure your specification is systematically organized and covers all the important topics.
- To assure that your specification includes the most recent equipment developments, government regulations and industry standards.
We believe all communities can benefit from the guide.
Existing standards applicable
It should be noted that the guide does not supersede, nor is it a substitute, for current standards (i.e., NFPA 1901, SAE, etc.) or government regulations (i.e., FMVSS, EPA, etc.). The guide explains these standards and where an option exists, the fire service user can introduce them into his specification as appropriate.
The guide is divided into five parts. Part I points out the need for the guide and explains how it fits into local purchasing procedures.
Part II gives a step-by-step procedure for fire department personnel to analyze and determine requirements for both road and pumping system performance based on local conditions. First, the fire department chooses a set of representative fire risks (present and/or future) in the community. A fire situation is made up for each risk and a prefire-like plan of attack is laid out on paper according to local tactics. Composite pumping system and other payload requirements (i.e., pump capacity, power required to drive the pump, tank size, hose-nozzle complement, supplementary equipment) are determined from these attack plans for all fire risks.
The weight of the payload is then estimated and a gross vehicle weight rating of the chassis is established as basic input into the road performance analysis which follows. Road performance requirements (i.e., acceleration, top speed, gradability) are calculated for a set of representative response route conditions in the community, considering response time objectives and cost implications of achieving them. Pump power requirements are also considered to ensure that both over-the-road and pumping objectives can be achieved.
Upon completing Part II of the guide, the department should have a set of justifiable performance requirements for the overall apparatus which are based on department objectives, an assessment of community road conditions, and representative fire risks.
Getting and using data
Parts III and IV of the guide are designed to be used together. Part III is a step-by-step workbook for developing the fire pumper specification data to be entered into the sample format which appears in Part IV. In Part III, each major subcomponent of the apparatus (e.g., engine, transmission) is presented and discussed. The presentation includes: (1) a glossary of technical terms, (2) explanations of relevant industry standards or government regulations, (3) a discussion of the performance/cost pros and cons of equipment options, and (4) a procedure for selecting or calculating performance parameters required for the specification in a manner consistent with the overall apparatus requirements determined in Part II.
The suggested specification format and wording in Part IV is designed for easy reproduction and completion by filling in the blanks, using the instructions and data determined in Part III. All main provisions normally included in a specification are covered. The format is flexible and systematically organized. The user can add to or leave out sections to meet specific local needs. The wording emphasizes performance with design details optional. Design and custom features are introduced into the specification only when needed— and then with a fuller appreciation of the performance and cost consequences.
In this regard, it should be emphasized that the specification appearing in Parts II and IV of the guide is not an ideal, or standardized, spec intended to fit the needs of all communities. We recognize that communities differ and that specifications must be tailored to satisfy individual needs accordingly. On the other hand, we hope that as fire departments throughout the nation begin to use the guide, similar requirements for similar communities may be grouped. This may lead to a few standard apparatus types that fit the needs of most communities.
Finally, throughout the guide, the involvement of all ranks in the department is stressed. The insights of company officers, engineers and mechanics can be particularly helpful in identifying apparatus needs. Moreover, the guide also emphasizes the importance of contact with apparatus manufacturers to check performance requirements and component choices to help spot potential cost, component matchup or other problems.
Nozzles and fire control
In addition to writing the specification guide, the project team also worked on areas offering performance improvements in fire apparatus technology. The results of this research are either incorporated into the guide or are the basis of related equipment standards or future work.
The project teams’s consideration of fire control performance standards and measurement techniques for nozzles is forming a part of an NFPA nozzle performance standard being developed by a committee headed by Chief William Patterson of Santa Barbara County, Calif.
Measurements have indicated that nozzles do not always deliver their rated flows. Furthermore, although fire fighters are aware of the application difference between the straight and fog streams, questions such as which specific characteristics of the form (i.e., water droplet sizes, etc.) directly affect reach and Fire control performance, how can they be measured, and how improvements might be achieved have not been adequately addressed.
The research indicated what might be done to more fully utilize water to improve fire control performance of nozzles and how this may lead to more effective fire fighting and safety. If improved fire control performance could be achieved, more intense fires could be controlled with a given hose size. On the other hand, if smaller flow rates could be used without reducing fire control effectiveness, smaller hose with less weight and lower nozzle reactions may be possible. This could mean quicker initial attacks with possible reductions in dollar loss and life safety improvements.
These developments might also enhance fire fighter safety by reducing the level of physical exertion and injury from nozzle reaction and from handling hose. Improved fire control performance would also reduce the time spent in a hostile environment and, with better water utilization, reduce loads from runoff water that contribute to structural collapse. Finally, these developments might ultimately permit reductions in the size and cost of pumpers.
Using road tests and computer techniques, response times and apparatus power levels studies showed that the acceleration and gradability performance of the apparatus significantly affects response times. Guide procedures were developed to aid the selection of performance levels properly matched to a community’s road conditions, response time objectives and budget constraints.
Based on experiments measuring the operational times associated with various evolutions, specific pump flow control response and accuracy requirements were established. Results generally showed that overall system response time was limited by hose handling and hydrant operations and that technology to reduce pump operation time provided only minimal benefit.
A study of human factors engineering developed specification guidelines to improve the layout of pump panel design. The objectives were to reduce pump operator training time, fireground operating time, errors and fatigue levels.