# lockoff
## English
### Alternative forms

lock-off

### Noun

lockoff (plural lockoffs)
* Any of various mechanisms that prevent a device or circuit from operating under certain circumstances, typically as a safety feature.
** 1953, Society of Automotive Engineers, SAE Transactions - Volume 61, page 138:A highly desirable feature is an atmospheric lockoff which tends to close the fuel line to the carburetor tighter as the pressure of the gas behind the valve increases.
** 1980, Frank E. McElroy, Accident Prevention Manual for Industrial Operations, page 415:Complex equipment may require that the movable members be in a particular physical position prior to actuation of power lockoff.
** 1997, National Alternative Fuels Training Program at West Virginia University, Natural Gas Vehicles, page 47:The fuel lockoff is an important component designed for leak prevention and fire control in accidents
** 2004, Mick Friend, The Encyclopaedia for Locksmiths, page 169:Each engineer will add their padlock through one of the holes in the lockoff and remove it once they have completed their task.
** 2013, E. A. Parr, Logic Designer's Handbook: Circuits and Systems, page 5:A local lockoff switch or an overtravel limit switch stops the motor regardless of the state of PB1 or relays A and B.
* A lockdown of part of a facility.
** 1972, Charles R. Tittle, Society of Subordinates: Inmate Organization in a Narcotic Hospital, page 48:On my way I got caught in a "lockoff" and security said nobody could move. When I told them it was an emergency, they just said that was too bad — it was a "lockoff" and I ought to understand the rules.
* (engineering) The act of fixing a ground anchor in place at a specific tension calculated to accommodate the expected load. Also, the tension at which the ground anchor has been fixed.
** 1975, United States. Federal Highway Administration. Offices of Research and Development, Report No. FHWA-RD, page 265:The amount of load locked into a tie depends upon the earth pressures and their distributions assumed for the wall . The following recommended lockoff loads are intended to serve as a guideline for use.
** 1989, Journal of Geotechnical Engineering - Volume 115, page 536:Measured lockoff loads varied significantly at each site , although the same jack and crew were used to install tiebacks at the Cullen Center and First City sites.
** 1991, Petros P. Xanthakos, Ground Anchors and Anchored Structures, page 313:Another movement mentioned in the foregoing sections involves wedge pullin of the anchorage type shown in Fig. 7-9, occurring at lockoff. In general, wedge pullin is monitored as indication of lockoff loss and the corresponding residual load at that time.
** 1994, Petros P. Xanthakos, Lee W. Abramson, Donald A. Bruce, Ground Control and Improvement, page 128:However, 30 months after installation nearly 45 percent of the anchors exceeded 105 percent the lockoff load.
* A device for securing a rope, strap, or cable at a particular level of tension.
** 1979, Anne Madden, More Sail Trim, page 236:The acceptance of lockoff has opened up new deck layout possibilities where winch placement and use can be made more flexible.
** 2001, Dennis Davis, National Tree Climbing Guide, page 66:If you will be moving around with your hands off the rope while you are tied off, further secure the lockoff by tying an overhand knot or two half hitches aroound the standing part of the rope with a bight from the running part of the rope.
** 2021 October 23, “Lockoffs and Belt Tensioners for Easy Installation of Carseats”, in carseatssite.com‎:Seat belt lockoffs have been on carseats for decades (yes, literally, thanks to Britax!), making installation so much easier.
* (climbing) The act of pulling down on a hold with one arm until the arm is fully bent at the elbow and using that arm to support one's weight.
** 2003, Will Gadd, Ice & Mixed Climbing, page 212:Start with your arm and shoulder fully extended, then smoothly pull the handle down into a full lockoff.
** 2018, Julie Ellison, Climb to Fitness, page 43:The stronger your lockoff strength (holding your arm in that position), the farther you can reach and the easier long, static moves will feel. If you're a shorter climber, lockoff strength becomes integral to progressing through the grades.
** 2022, Volker Schöffl, Isabelle Schöffl, Christoph Lutter, Climbing Medicine: A Practical Guide, page 135:Most often, the injury mechanism is described as a sudden force on the flexed and supinated forearm by pulling on an undercling into a "lockoff” position followed by a clicking sound [11].
* (film) A type of shot in which the camera is fixed to a mount and unable to move.
** 2001, Karen Goulekas, Visual Effects in a Digital World, page 325:A shot in which the camera changes position, via a pan, dolly, truck, crane, and/or boom, during the filming of aciton. Opposite of a lockoff shot.
** 2008 October 20, Brad Grimmett, “Operated camera vs. locked off shots”, in cinematography.com‎:In my experience, a completely static shot is more noticeable than a shot that makes subtle adjustments for things like headroom, which is essentially what you're talking about. I think most of the time those slight adjustments are needed to keep a shot properly composed, but when you do do a complete lockoff it stands out and can have a nice effect.
** 2013, Erica Hornung, The Art and Technique of Matchmoving, page 90:But for a rack, unlock the focus channel, lock the rest of the channels (assuming this is a lockoff shot—racks usually are), and then solve for the lens.
** 2016 June 13, Ian Smith, “Annabelle Serpentine Dance is the world’s first hand-tinted motion from 1895, and it’s quite spectacular”, in The Vintage News:The dance is performed in succession in a lockoff shot.
* A timeshare that allows a section to be sealed off from the rest of the unit and rented separately.
** 1988 October, A.R., “Bedspeak”, in Ski, volume 53, number 2, page 178:Living in a lockoff is fine for people who want to be alone together, except when they go out to eat.
** 1995, Vacation Industry Review, page 21:Hillside villas will have an eight-person sleeping capacity and lockoff capability , with a second kitchen and sitting room adjoining the second bedroom . "
** 2008, Resort Real Estate and Clubs, page 1085:Are there any lockoff units ( i.e., where one unit is actually comprised of two living spaces that can be occupied separately if desired)?