ISSUE DATE: 04/03/2012

PROGRAM INFORMATION BULLETIN NO. P12-07

FROM: JEFFERY H. KRAVITZ

 Acting Director of Technical Support 

 KEVIN G. STRICKLIN 

 Administrator for 

 Coal Mine Safety and Health 

 NEAL H. MERRIFIELD 

 Administrator for 

 Metal and Nonmetal Mine Safety and Health 

SUBJECT: Neutral Start Methods on Mobile Electrical Equipment

Who needs this information?

Mine Safety and Health Administration (MSHA) enforcement personnel, coal and metal 

and nonmetal surface and underground mine operators, miners' representatives, 

equipment manufacturers, and repair shop facilities. 

What is the purpose of this Program Information Bulletin (PIB)?

The purpose of this PIB is to inform interested parties of a potential hazard that can be 

eliminated by providing a neutral start method on mobile electrical equipment. This 

PIB supersedes P09-07.

Information

What is a neutral start method?

A neutral start method is a design feature which ensures that machines cannot be 

started unless the drive (tram) control is in neutral. This ensures that motor torque will 

not be transmitted unintentionally to the drive motors and cause machine movement 

when electrical power circuits are energized on the machine. A neutral start method 

also prevents electrical equipment from changing direction with the foot control 
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depressed and when the directional control is switched from one direction to the other 

(directional control interlock feature) until the foot control is released to the neutral 

position.
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Why is a neutral start method needed?

The lack of a neutral start method can create a dangerous condition for persons working 

in the vicinity of equipment, who might be caught unaware by the sudden movement 

of the equipment when the equipment becomes energized. Without a neutral start 

feature, it is possible to start a machine and deliver power to the driving mechanism 

resulting in unintentional movement of the machine or enabling the machine to change 

direction with the foot control depressed before the equipment operator is in total 

control of the machine. This hazard applies to machines with direct-drive electric 

motors, as well as machines utilizing fluid power or other systems for the drive 

mechanism. For this reason, MSHA recommends that mine operators and equipment 

manufacturers equip all mobile electrical motor-driven machines with a neutral start 

feature as soon as possible. For further guidance on equipment modification, contact

the equipment manufacturer. If the equipment being modified is permissible, the 

approval holder or mine operator should contact MSHA's Approval and Certification 

Center to ascertain whether the equipment modification affects the permissibility of 

such equipment. 

What is the background for this PIB?

An accident occurred while a shift foreman was preparing to tram a belt feeder after a 

belt move. When the feeder was energized, it started the driving mechanism, which 

caused unintentional and uncontrolled machine movement, resulting in the machine 

pivoting abruptly and pinning the victim between the feeder and the coal rib. 

Another accident occurred when a mantrip was traveling in reverse and became stuck

on a pile of coal. The foot control remained depressed and the machine operator 

changed the directional control switch to forward. The mantrip lunged forward and 

pinned a miner against the coal rib. These accidents and other similar accidents could 

have been prevented if the machine involved had incorporated a neutral start feature. 

The incorporation of a neutral start feature will have a minimal impact on retrofitting 

electrical equipment in the field. Neutral start features have been successfully 

incorporated into underground permissible diesel-powered equipment for over 25 

years and should also be incorporated into other mobile electrical equipment. Several 

manufacturers already have incorporated electrical circuits to prevent tramming of 

equipment if a directional control or footswitch is activated unintentionally during 

start-up. Other pieces of equipment have incorporated circuits to prevent a hydraulic 

motor from starting, unless the directional control for the electric tram motors is placed 

in the "off" or "neutral" position when the hydraulic motor is energized. Additionally, it 

is possible to devise a neutral start feature through a mechanical linkage which would 

prevent the ability to start the machine unless the tram controls are placed in a "neutral" 

position. 
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What is MSHA's Authority for this PIB?

The Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. § 801 et seq., 30 

C.F.R. §§ 18.20(b), 56.14100, 57.22302, 57.22303, 57.22304, 57.22305, 75.1725, and 77.404. 

Is this PIB on the Internet?

This bulletin may be viewed on the Internet by accessing MSHA's home page 

(http://www.msha.gov) and then choosing "Compliance Info" and then clicking on 

"Program Information Bulletins." 

Who are the contact persons for this PIB?

Coal Mine Safety and Health, Safety Division

John Arrington, (202) 693-9549

E-mail: arrington.john@dol.gov

Metal and Nonmetal Safety and Health, Safety Division

Brian Goepfert, (202) 693-9600

E-mail: goepfert.brian@dol.gov

Technical Support, Approval and Certification Center

Kenneth Darby, (304) 547-2006

E-mail: darby.kenneth@dol.gov

Who will receive this PIB?

MSHA Program Policy Manual Holders

MSHA Special Interest Groups

Surface and Underground Coal and Metal and Nonmetal Mine Operators

Repair Shops

Manufacturers of Electric Mining Equipment