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Magnetic locks secure openings with greater holding power and a more secure
point of attachment, when energized. A magnetic lock is a heavy metal
block that requires professional installation and continual maintenance.
The magnet consists of wound copper coils enclosed in a metal case. The
contact plate, also known as the armature plate, attaches to the door
in most cases, and bonds to the magnet when energized. Both components
can and do become loose if improperly installed and/or poorly maintained.
Injuries that result from falling magnetic lock components are common.
This does not mean that they are acceptable or unavoidable. In most cases,
improper installation techniques combined with inadequate maintenance
and substandard observation are the reason for these injuries.
Magnetic locks are commonly used where access is restricted.
Typical installation locations
- Bank ATM vestibules for after hour commerce
- Passage points in facilities that want to limit entry to secure or hazardous areas
- Psychiatric wards where patients must be safely contained.
- Access gates and controlled entry points in parking structures.
- Office building entry points
- Penal institutions
- Limited access stairwells,
- Apartment buildings, hotels, hospitals, labs, condos, and a multitude of
other installations that require restricted access where a manual key
entry system is cumbersome, impractical, or inadequate.
Magnetic locking devices range in size and weight depending upon the holding
power required for the specific location. In general, the size of the
device is indicative of the available magnetic potential holding power.
Some units are integrated into a systemic alarm system with back up failsafe
features that keep the lock active, while others are stand-alone units
that can lose function when the power is turned off.
Magnetic locks generally use a copper wound coil to generate the magnetic
field when coupled with a steel armature plate. Most installations have
the field coils located in a rectangular box installed on a fixed point
such as the header of a door frame. Using concealed wires, the fixed electromagnet
contained within a metal housing is powered through the frame of the door
and the access release point. Either a card key swipe, old-fashioned metal
turn-key lock, or other activation device momentarily disconnects the
power, interrupting the magnetic field, allowing the door plate to release
from the magnet and grant access to the user. In most installations there
is a timer set to allow a specific entry time prior to reactivation of
the magnetic field.
Due to the materials needed to produce a strong magnetic field, both the
steel plate armature and the wound field coils can be quite heavy. These
heavy materials require specific attachment and proper installation techniques.
As a consultant to hardware manufacturers, it has always been my professional
opinion that one of the most basic installation practices along with utilization
of good quality appropriately sized and rated installation bolt hardware
is to use a thread locking agent. Thread locking agents are designed to
essentially glue the threads of a bolt to the tapped hole. Thread lock
is now often provided with many hardware manufacturers products in the
form of factory applied dry thread coatings or a small tube or bottle
of permanent or semi-permanent thread lock liquids.
Depending upon the desired rating of the mag lock, the integration with
the door and frame or gate and frame is critical. In repeated magnetic
lock installation failures (where components have fallen on people) it
has been found that improper hardware has been used for installation.
Screws, bolts, or other fasteners were found sheared from usage or the
holes where the bolts or screws were installed had been stripped due to
improper drilling and tapping. Inadequate thickness of the attachment
point backing base materials is also a common cause of disconnection.Read Michael Panish’s
Mechanical Fasteners article that discusses injury cases where products that become disconnected from
their point of attachment have resulted in serious bodily harm.
Magnetic locks are continually “challenged” due to denied access.
They are often not deactivated as expected due to inappropriate codes
entered from attempted access points and hold the door closed in the frame.
A user may have incorrectly entered an access code, a key card may be
unauthorized for entry or the entry point may be turned off for usage
due to security reasons. Depending upon the amount of activity for the
subject doorway, a magnetic lock can be subjected to years of abuse from
these denied entries numbering hundreds of thousands of attempts.
Denied access creates stresses on the points of attachment of both the
fixed magnetic coil box and the steel plate that is usually attached to
the door with some sort of a swivel connection. If properly configured,
a hollow metal door and frame will be manufactured with specific backing
plates built into the components that are capable of positively anchoring
a magnetic locking system. If proper installation techniques are performed,
the hollow metal frame and backing plate will be professionally tapped
for the correct bolt hole size. The bolts will engage a solid steel backing
block and the bolts will have adequate thread penetration to provide definitive
attachment. The installation should utilize a high tensile and high shear
strength bolt and chemical thread locking agents will assure long term
attachment of the components.
Even with proper placement and professional installation, magnetic locks
can become loose. Due to the continuous tugging on an unreleased magnetic
lock, the weakest component will often become the source of detachment.
That is why it is critical that routine inspections are made of all magnetic
locks. Appropriate standards and practices dictate that these inspections
should be made by the management of the facility as well as professional
service providers. The frequency of inspections depends upon the usage
and security requirements of the location and the type of materials used
to anchor the magnetic device. Some installations of magnetic locks have
used wooden doors and frames. If properly attached and monitored a wood
system can provide light duty magnetic lock security. Due to the inherent
weakness of wooden doors and frames, openings that have magnetic locks
in place, must be closely observed for points of failure.
In higher security installations where magnetic locks are installed, routine
monthly or weekly tests of the openings place additional challenges on
the door and locking system. Proactive testing to verify that the magnetic
lock is fully functional ranges from basic manual pull tests made by a
facility staff member to a platform rig designed to quantify and prove
the holding strength of the lock. These tests place strain on the points
of attachment and should be coupled with a physical examination of the
substrate, holding bolts and all components of the lockset to determine
that the substructural elements are intact and the components have not
cracked or begun to fail in any way.
As a door and gate legal expert, I am contacted frequently regarding injuries
due to falling magnetic lock components. I have been the retained expert
on numerous legal cases where a magnetic lock failed to work or did not
stay attached to the door and frame, as required. Falling magnetic lock
components have created serious injuries and wrongful death claims. These
claims have happened from diverse locations such as security doors for
banks, shopping centers, hospitals, labs, penal institutions, long term
care facilities, and hotels - among others. The reasons for these claims
vary according to location.
INJURY CLAIM EXAMPLES
The following are examples of injury claims common to many cases involving
magnetic locking systems:
- An ATM (Automated Teller Machine) vestibule used after hours had a magnetic
lock drop from above onto a bank customer as she attempted to enter the
area. The entire incident was recorded on video footage and clearly showed
that the customer had no warning and did nothing to contribute to this
injury. Recent repairs had been made to the door and frame by a professional
service provider that did not address the points of attachment or loose
condition of the installation of the magnetic lock system. The bank management
relied upon the service provider for the original installation and ongoing
maintenance of the doors. The bank was never informed by the service provider
that any routine inspection or other proactive measures were needed regarding
this specific locking mechanism. The bank took the position that the service
provider failed to professionally install and maintain the lock mechanism,
and the service provider had the full responsibility for inspections and
- A patient in a psychiatric ward (which was known as a high-risk elopement
location) became violent, rushed a magnetically locked hallway door, overcame
the door through his superhuman strength and ran out of the facility.
The patient ran into passing vehicle traffic and was hit by a car and
killed. The lock, door, and frame had been improperly maintained and the
magnetic force generated by the lock was inadequate to contain this violent
patient. When inspected, the magnetic lock that was originally rated for
2500 pounds of holding power was tested and could not maintain a 300-pound
pull. The door and frame were found in an extremely deferred condition
and the magnetic lock had not been professionally inspected or tested
for many years prior to this elopement incident. The maintenance department
of this facility was improperly trained and did not perform any routine
tests of the magnetic holding power, as was required by the management
of the health care facility.
- In a penal institution, Sally port gates controlled by magnetic locks had
an armature fall on an inmate as he was passing through the opening while
being transported to another location. The gate was approximately 14 feet
tall, and the steel mag lock component that dropped on the inmate weighed
approximately 7 pounds. The inmate sustained a TBI (traumatic brain injury)
and spinal compression from the falling component. The incident was recorded
on the facility video cameras. The gates and locks had not been inspected
for appropriate attachment for at least 2 years prior to this incident.
The gates where the mag lock dropped from were being used on a daily basis.
- A resident of a large apartment complex used card key access to unlock
the main entry doors to the lobby. As he was passing through the door
pair the heavy magnetic coil of the magnetic lock dropped from the door
frame. The 16-pound magnet coil and box swung, dangling only by the supply
wiring in an arc straight into the tenant’s face breaking his nose
and eye socket. Video footage clearly showed the incident in real time.
It was discovered that the building janitors had been notified that there
was a problem with the front doors and attempted to perform in-house repairs
rather than contact a professional service provider. The mag lock was
improperly reinstalled by the janitor using undersized screws that did
not hold the lock to the frame. Prior video footage from the same day
of the incident showed the magnetic lock dropping from the frame and swinging
with the same wire 6 hours before the injury incident.
The above examples are just a few scenarios of injuries caused by improper
maintenance and attachment procedures. Magnetic locks are heavy and sharp
boxes that fail in many ways and they frequently lead to personal injuries
including traumatic brain injury (TBI). There are installation techniques
and procedures that generally make these devices safe, if professionally
followed and performed. Routine inspections and testing require trained
personnel to determine the overall installation and verify that the working
condition of the lock is safe for use. Failing to inspect and maintain
any door hardware can lead to injuries, but when a magnetic lock falls
from overhead it can be deadly.
Michael Panish provides legal expert services for plaintiff and defense
claims. He is nationally recognized as an authority on automatic door
access points, doors & door components, and gates, and as of 2020,
has been retained on over 1600 legal cases since the year 2000. He is
a licensed door, lock, and security equipment contractor in the State
of California and has installed and serviced door related hardware products
since 1976. Mr. Panish can be reached at (888) 902-4272 (ask for Sharon),