Letters to the Editor
Thoughts, criticisms, and new ideas offered on lubrication systems article
The article “Proper Lubrication Reduces Engine Wear” by Jerry Shelby in the March issue appears to offer a minimal solution to a complicated problem. The article was predominately turbocharger-oriented, and the information on turbocharger lubrication was somewhat misleading.
Major consideration should be given to manufacturers’ recommendations for using add-on units. This is the most commonly used system for turbocharger prestart and shutdown lubrication systems, before installation.
Studies have shown that turbocharger lube systems, other than those that are factory-engineered, can be an additional cause of failure. Fittings may loosen, supply lines may break, or secondary pressurization components may fail. A fire apparatus has many demands placed on it. To use a turbocharger lubrication system that isn’t factory-recommended is an unnecessary added risk.
Mr. Shelby also suggests using multigrade (15W40) oil to reduce wear at startup. He says thinner oil will pump and flow to critical components more easily than thicker oil. Sound advice if the engine is subject to a 5° F temperature (-15° C) at startup. However, most fire apparatuses are stored in heated facilities. Freezing temperatures are rarely encountered at startup.
Engine oil performs several basic functions to provide adequate lubrication. It keeps the engine clean and free from rust and corrosion, it acts as a coolant and sealant, and it provides an oil-film cushion that keeps metal-tometal contact to a minimum. A lubricant’s main function is to reduce friction and wear by maintaining an oil film between moving parts. Film thickness and its ability to prevent metal-tometal contact of moving parts is related to oil viscosity and additives.
Viscosity is one of oil’s more critical properties. It refers to an oil’s thickness or its resistance to flow. It can be defined as the resistance of one laver of oil to movement while another layer in contact with it remains fixed. The viscosity level is directly related to how well an oil will lubricate and protect surfaces that contact one another. The more viscous (thick) an oil is, the thicker the oil film it will provide, thereby making it more resistant to being wiped or rubbed from lubricated surfaces. However, the thicker the oil is, the more resistant it becomes to flow at low temperatures. Ambient temperature becomes the critical factor for oil viscosity at startup and should be a focal point when you’re selecting a grade of oil.
Multigrade oils such as 15W40 contain polymers called viscosity index improvers (Vlls). There are several general types of VII. The VII polymer allows the oil to exhibit low viscosity in cold temperatures and high viscosity at elevated temperatures. A side effect of these polymers is that they tend to break down (shear) after relatively short-term engine operation. Shearing is the physical breakdown of polymers due to mechanical and thermal stress, resulting in viscosity reduction and premature engine wear.
Shearing occurs due to reduced viscosity and results in thinner oil film; at the same time, the oil pressure drops. Thus, 15W40 may be reduced to 15W20, depending on the type of VII polymer that’s used in a short operating period. This phenomenon is known as permanent shear.
VII polymers are also susceptible to temporary shear, an instantaneous phenomenon that occurs at the boundary of highly squeezed film lubrication areas. This temporary shearing may bring an oil’s viscosity down to 15 grade (the base stock), which is inadequate at diesel engine operating temperatures.
Before you use a certain oil, study the engine manufacturers’ recommendations and implement a comprehensive oil analysis program.
Douglas T. Stolar
Administrative Assistant
to the Deputy Fire Commissioner
Bureau of Support Services
Chicago Fire Department
Chicago, III.
Work to improve your department’s insurance rating
Congratulations go out to the Egremont Volunteer Fire Department in South Egremont, Mass., for its dedication, hard work, and success in improving its insurance rating to Class 6. [See “Increasing Standard Operations” by William W. Weigle in the January 1987 issue.]
I realize what they went through, because we here at Mt. Hope Volunteer Fire Department in Julian, N.C., just took the same big step in September 1986.
Shortly after our department was formed and chartered in December 1972, it achieved a Class 9A rating. We kept this rating, and through the years we continued working and training to improve ourselves and our service to the community.
The hard work paid off. Like the Egremont Volunteer Fire Department, we also improved our rating to Class 6.
Our department consists of one station, 30 volunteers, and one full-time firefighter. We provide coverage to a district that emcompasses approximately 30 square miles. With only one 750-gpm pumper, one 450-gpm tanker, and one 260-gpm four-wheel-drive minipumper, we haul a total of 2,260 gallons of water. We also have 11 dry hydrants and no pressurized hydrants. Considering the limited equipment and manpower of our department, I thought we did an excellent job to achieve a Class 6 rating.
Since we received our new rating, several of our neighboring departments are making preparations to apply to be rated. I hope that other small departments throughout the country will be inspired by the results of our department and the Egremont Volunteer Fire Department. Remember, hard work and cooperation can help your department improve its insurance rating.
Byron Greeson
Captain
Mt. Hope Volunteer Fire Department
Julian, N.C.
March editorial on Puerto Rico hotel fire elicits comments and a correction
Your March editorial (“Lessons? How Many Times?”) covered at least two issues that have slowly driven me “nutso” during my 24-plus years of involvement in public fire protection.
The first major point, concerning the Dupont Plaza Hotel fire, focused on the idea that “we are still in the grip of debates … This indicates there may be a general problem with establishing appropriate standards in the model code process.
The second major message I received from your editorial was that sprinklers work. While I am sure that every fire professional who has read the editorial agrees with it completely, I also know that there are several of us who continue to believe that the fire service is missing some major points. Why, for instance, do we continue to pommel each other with information that we have already known to be accurate for decades?
I continue to marvel at the modern fire service as it conducts in-depth fire investigations of our failures using the best minds our country has to offer so that we can be told, yet again, what the problems are (were).
It doesn’t take a Ph.D. to determine what our problems are. The terms fire and life safety plan reviews, technical inspections, maintenance inspections, etc., have been around long enough to make even the most unobservant firefighter aware of what’s needed. Now that we know what’s needed, how do we go about making it happen?
Somewhere along the line, our priorities got screwed up. I know the old saw. Throughout my career, I’ve been involved in attempts to “sell” policy bodies on the economic and life safety value of built-in fire protection systems. Lacking the time or inclination to become sufficiently educated to make “the right decision,” we’ll probably continue to receive negative responses to these requests for support.
I appreciate very much this opportunity to share some of my thoughts with you. If you know of any attempts at any level to effectively disseminate information on this social phenomenon toward the end that behavioral modification (read that “positive political acceptance”) may realistically be expected, I’d be extremely happy to become involved with such an effort. Let’s stop beating each other over the head with what turns out to be old information. Let’s beat some folks over the head who can make some changes happen!
Kenneth R. Morss
Division Chief
Fire Prevention
Tualatin Fire District
Tualatin, Ore.
Editor’s reply: We share your interest in learning of and supporting efforts at improving life safety, and we encourage readers to keep us all informed by sending replies to your questions here for publication.
I’ve always had high regard for Fire Engineering. It’s been part of my reading since I started subscribing as a teenager many years ago.
As I read this and other magazines, I come across certain errors that catch my eye—such as SCBA tanks that are called oxygen tanks instead of air tanks. When this happens, I usually bring it to the editor’s attention in a constructive manner.
Your March editorial (“Lessons? How Many Times?”) referred to the Dupont Plaza Hotel fire in Puerto Rico. However, you called it the Dumont Plaza Hotel fire.
As you well know, many people don’t report a fire because they think someone else has already done it. This causes many delayed alarms. I write this comment in that same vein—not wanting to overlook a somewhat outstanding misrepresentation or typographical error, as the case may be.
Best wishes for continued forward motion with Fire Engineering.
Andrew A. Ayers, Jr.
Account Executive
Engineering Equipment Co.
Downers Grove, III.
Editor’s reply: The point is well-taken. I’d like to know the number of lives and amount of property that would have been saved through the years had the correct address been given or ascer- tained on receipt of an initial alarm.
I’m never one for excuses, and true is true. However, the shuffle in changing locations and publishers does have costs as well as benefits. The confusion allowed some m’s to slip into spots where p’s belonged. I apologize to our readers for this and am glad to take the rap. M or p—we still have no lessons at Dupont Plaza, only more examples.
—Tom Brennan, Editor
Members benefit from “Games”
The article “Games” by Mike Ventimiglia in the March issue has made my job easier. I’ve been a volunteer in our department since its inception in 1975 and have seen chiefs come and go. Now we’re changing chiefs again.
We’re a small department, and I’ve been trying to tell the personnel what to expect, but they couldn’t understand. The “Games” article put into words what I was trying to get across, and now the members understand. Thanks for making my job easier.
Russell E. Agee
Assistant Chief
Golden Valley Fire Department
Kingman, Ariz.
We enjoy hearing from our readers. In addition to sending comments, you’re welcome to send questions that come up as you read articles here; we’ll be happy to forward them to our authors. Whether you have questions or comments, write to Fire Engineering, 250 Fifth Ave., New York, NY 10001.
