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When facing barricade and hostage scenarios, clinical staff told us they just want to know they can get access when they need it.  That’s why we developed the most complete override locking system on an anti-ligature lockset – 5-way SOS (Staff Override System).  

In the most common barricade scenario – where a service user is holding the internal turn/pull – the staff key dominates the internal turn/pull (“key override”), ending the barricade quickly and simply. 

For determined barricade attempts – where the keyway is blocked or the service user has jammed the turn/pull – there are four additional emergency override methods, ensuring staff can always get access – providing peace of mind and saving lives.

The result?  A lockset that's been tried, tested and proven in challenging Mental Health environments to keep service users safer.



1. Key override

The lock and the internal turn/pull operate independently, so the key always dominates. It’s a direct mechanical override, so there’s no geared cylinder to disengage the turn/pull or clutch mechanism involved.


2. Keyway override

Concealed backup override directly turns the spindle, allowing entry if keyway is blocked with foreign objects, like chewing gum or paper.

3. Turn leverage override

T-bar emergency tool provides superior leverage to rotate the turn/pull, even if the service user is stronger.

4. Spindle override

Spindle shears under heavy resistance, ensuring entry if turn/pull is immobilised. So even in the most serious barricade attempts, where the service user attempts to jam the turn/pull with their bed or body, swift access is achieved without lockcase damage.

5. Pull advantage override

T-bar provides significant power advantage to pull the door open – offering better grip than an anti-ligature handle and foiling attempts by a service user to hold the door shut.

Overcoming simple barricades


With either our 1-way SOS or 5-way SOS locksets, the majority of barricades are easily resolved by staff operating the lock with their key – ending potentially stressful situations quickly, safely and without damage.  

Our patented direct mechanical override system prevents service users from holding the internal turn/pull to create a barricade – because the key always has priority.

Because this turn/pull operates independently from the key, it removes the need for a clutch cylinder, which can slip under side pressure. It also means that a geared cylinder, which can be manipulated by over-rotating the turn/pull, is no longer required.

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Overcoming determined barricades


Designed to provide complete peace of mind, our 5-way SOS locksets provide multiple ways to overcome even the most determined barricade attempt. So while these situations are rare, clinical staff know they are properly prepared to keep service users safe in their care.

Limitations of alternatives




Our research into existing override systems uncovered several limitations – which we designed out of our Staff Override System.

Clutch cylinders

Clutch cylinders

When a service user holds the internal turn/pull to create a barricade, the catch is designed to slip at a higher torque. Operating on a spring and ball-bearing mechanism, the key then turns and unlocks the door.

Over time, however, doors moveexpand or distort, limiting clutch effectiveness and making entry times longer in stressful situations.

Wear and tear can also cause the clutch to permanently slip – trapping service users inside and causing distress and fire safety issues.

Geared cylinders

Geared cylinders

When the key is put into a geared cylinder, it mechanically disengages the internal turn/pull, allowing the door to be opened.

However, service users can easily rotate the turn/pull past its maximum closed position, preventing the key fully engaging. Although the key can eventually be forced home, it can damage the cylinder and the key may snap, causing risk of injury and prolonging the barricade because of a blocked keyway.

Issues also arise in rehabilitation or step- down units, where service users may have their own key. This can be inserted into another service user’s lock, disengaging the turn/pull and locking them inside, resulting in anxietydisruption and fire safety risks.

Square drive override

Square drive override

Square drive mechanisms are sometimes used on anti-barricade locksets to unlock the door when the keyway is blocked. However, the small square drive key doesn’t always provide enough turn leverage – allowing a strong service user to prolong a barricade by tightly holding or wedging the turn/pull.

Because the square drive key simply pulls out, it provides no pull advantage or improved grip to open a door outwards.

Plus the insecure square mechanism can easily be rotated – with two spoons, for example – minimising security and creating privacy concerns. Circular shaped mechanisms can reduce this particular risk.



Glasgow office

Level 4, Skypark 3
14 Elliot Place
G3 8EP

t: 0330 058 0988

Blackpool office 

Unit 8 Bankfield House
250 Bristol Avenue

e: info@safehingeprimera.com


© Safehinge Primera 2018.  Design By Submarine. Development By Crocodiles
Safehinge Primera is a trading name of Safehinge Limited (SC304496) and Primera Limited (03708136)