Jefferson Lab > ES&H
Privacy and Security Notice
ES&H Manual
Chapter 6112 Interlock Bypass Program
Interlocks serve to protect personnel and/or equipment by constraining the operation of equipment, either electronically or mechanically, and typically rely on a transducer, sensor, switch, or other physical mechanism to keep equipment from being placed in an unsafe state.

From time to time it may be necessary to bypass a system interlock. Jefferson Lab's Interlock Bypass Policy describes the administrative requirements for bypassing system interlocks on equipment.

NOTE: This policy does not apply to equipment associated with the Personnel Safety System (PSS), which is governed by the Jefferson Lab Personnel Safety System Configuration Control Policy.

Any maintenance or service work associated with hazardous energy sources are subject to Lock, Tag, and Try (LTT) as described in ES&H Manual Chapter 6110 Lock, Tag, Try (LTT) Program.

Bypassed interlocks are identified by an applied Interlock Bypassed tag and/or electronic entry in the Accelerator Bypassed-Interlocks Log (ABIL). Specific steps used to identify bypasses depend on whether the equipment is in service or out of service.

This policy defines the requirements, responsibilities, and qualifications necessary to identify installed interlock bypasses on equipment at Jefferson Lab.

Table 1: Required Safety Training by Job Classification

Training Course Qualified Bypass Interlock Individual
Bypassing Interlocks


T1 Interlock Bypass Procedure
ES&H Manual Chapter 6112 Appendix T1 Interlock Bypass Procedure outlines the administrative requirements for identification, installation, and tracking of bypassed interlocks.

Note: Management authority may be delegated at the discretion of the responsible manager.

Qualified Bypass Interlock Individual
  • Obtain training in SAF 144 Bypassing Interlocks.
  • Know the location of blank Interlock Bypassed tags.
  • Properly fill out an Interlock Bypassed tag and/or enter ABIL for each bypass you install.
  • Keep ABIL entries current by ensuring they are removed on or before the removal date, or if necessary change the removal date prior to its expiration.
System Owners
  • Be aware of any bypasses entered in ABIL for equipment installed in your system, and coordinate with the person who installed the bypass, as necessary. (ABIL will automatically send email notifications of bypasses installed in your system.)
  • Designate an alternate System Owner via email to ABIL Administrator.
  • Using the Job Task Analysis (JTA), identify individuals under your authority who are assigned to bypass interlocks.
  • Ensure training is current with SAF144 Bypassing Interlocks for Qualified Bypass Interlock Individuals under your authority.

Document Control:
    APPROVAL DATE:   10/13/16
    REVIEW DATE:  10/13/21
    Revision 0.3 - 10/13/16- Periodic Review - updated TPOC from R.Lauze to K.Baggett.
    Revision 0.2 - 05/20/14 - Added Required Safety Training Table.
    Revision 0.1 - 12/17/13 - Added invisible links to "Martha" program in subparagraphs per MJBailey.
    Revision 0.0 - 08/05/13 - New content written to reflect current laboratory operations.

This document is controlled as an on-line file. It may be printed but the print copy is not a controlled document. It is the user's responsibility to ensure that the document is the same revision as the current on line file. .