Securing garage door with narrow frame

[Jon12345]

I want to add some security to this door since there is no lock on it. The wood strip to the right of that door handle is 36mm wide, and slightly raised prefab concrete after that. The challenge is the narrow width of that wooden strip.

How would you deal with this to make it secure?

 

[motorbiking]

Some external shoot bolts (perhaps with a combination lock) and padlocks or even some U bolts and a motorcycle chain lock.

The other option is mortice lock mounted on a raised block inside of the door/gate if it’s too thin.

 

[ReganAndCarter]

Wondering if there's enough width on that frame to get an internally surface mounted rim lock on there. Looks like there is was one before.

Rim Lock with Handles

Need to fit a lock to a timber door? The ERA rim lock is perfect for sheds, gates or other internal doors - it comes complete with fixing and two keys, plus matching black door knobs. Suitable for use on left or right-handed doors.• Perfect for inward-opening shed or timber doors• Suitable for...

www.toolstation.com

Or an external gate lock with coach bolts through door for extra security.

https://www.screwfix.com/p/gatemate-black-double-long-throw-lock-50mm-154mm/386YV?gclsrc=aw.ds&gad_source=1&gad_campaignid=19815174711&gclid=Cj0KCQiA4eHLBhCzARIsAJ2NZoJOzWbQtZrFd9HClRKt3IasAcF3EmUE-8y_WA0BB4kMx-6bbgC-jRsaAmM1EALw_wcB

 

[Jon12345]

Wondering if there's enough width on that frame to get an internally surface mounted rim lock on there. Looks like there is was one before.

I just opened the door and blimey, there is already a rim lock there! So, considering I do not have a key, I could just replace it. And then also put a brenton bolt on there for added security.