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Antique Safes/Mosler Cannon Ball Safe


Mosler Safe
Mosler Safe  
Our museum has a Mosler Manganese Screw Door (Cannonball) Safe; Model #OS110, Size #3, S/N 219463. this safe was in a Bank when it closed, so it is unlikely that the timers were set the last time it was closed. The outer (Day Lock) door is open with the lock in the locked position, however when the door crank is inserted and rotated to open the main door it will only move about 1/4 inch in rotation and feels like it hits something solid. I can provide detail photos if that will help. Let me know where to send them if desired.

2 Questions:
1 - Do you know what the failure mode of the internal timer locking mechanism is (Pin out or in)? Or have any suggestions on how to get the main door open?

2 - What is the process to reset the combination on the outer door combination lock? I believe it is a Mosler Model 5H, but can not find any identification on the exterior of the lock.

Hi Robert,

Beautiful safe!    As you have described, the outer, small door is simply the day lock.    The inner lock is a time locked, automatic lock, only designed to secure the door of the safe for a period of time - up to about 72 hours.

Unfortunately problems like this tend to be hands on diagnostics and repairs.    Over an email, all I can do is to speculate what the problem is.

This safe door is a screw door type cannon ball safe.    Meaning that there is a very large thread on the inside portion of the door jamb that the door fits into.   It has one or two large locking lugs, that when extended lock the door in place so that it can't "unscrew" and open.

It is not unreasonable (based on your description) that one or both of these lugs may not be attached to the time lock and/or the time lock may have quit with time left on it.

The lock is either a three or four wheel hand change lock, meaning that it is necessary to completely disassemble the wheel pack to change the combination.    This is not a DIY project.

Bottom line - my recommendation for either item would be to have a trained safe technician work on the safe.    While the combination changing will be quite standard for a safe tech, you may need someone with more knowledge and training to work on the main door.

While it may be something simple blocking the door from opening, worse case it will have to be drilled and repaired.

If you don't have any trained safe technicians or companies in your area, let me know where you are located (zip code) and I'll see who I might know nearby.

Sorry I can't be of more help at this time.  

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Terry V. Andreasen (Andy)


Safe and Vault related Questions; Antique Safe Repair and Restoration; With over 44 years in the Safe & Vault industry, if I can't answer your question I know where to get the answer. Current Project: Restoration of an Ely Norris Cannonball Safe from the early 1900's. Will answer Safe & Vault related questions concerning age, value, restoration, moving, opening & repairing, parts, operation and history. Note: It is not my intention to teach you to open safes or to provide information which may aid in the unlawful opening of a safe. I will not give out drill points or information which I deem inappropriate.


44 years in the Safe & Vault Industry. Owner and Service Manager for one of the largest Safe & Vault companies on the West Coast. Graduate of Lockmasters Safe Lock Servicing, Safe lock Manipulation and Safe Deposit Lock Courses. Graduate of Locksmith Institute. Author of "The Coffee Table Guide to Antique Safes". Certified Instructor for the California Locksmith Association teaching Basic and Advanced Lock Servicing, Basic Safe opening and Repairing. Factory Trained by AMSEC, LORD Safes, LeFebure, Mosler, KabaMas, LaGard and Sargent & Greenleaf

Safecrackers International and the National Antique Safe Association Safe & Vault Technicians Association

The Coffee Table Guide to Antique Safes

Graduate of Locksmith Institute 1972 Graduate Lockmasters Safe Lock Servicing 1974 Graduate Lockmasters Safe Lock Manipulation 1975 Graduate Lockmasters Safe Deposit Lock Servicing 1985 Instructor Certified - California Locksmith Association - 1985 Factory trained by AMSEC, MAJOR, STAR, Johnson-Pacific, Kaba-MAS, Allied-Gary, ISM, Lord, Brown Safe, EXL, Mosler, Diebold.

Awards and Honors
2009 - 2015 Listed in AllExperts top 50 Experts. All Experts Categories - Safes & Security Containers, Locksmithing, Antique Safes. Retired US Army Chief Warrant Officer (CW4), with 39 years of total service. With numerous awards from Vietnam, Desert Storm and Operation Iraqi Freedom. US Navy - 1971-1981 US Army Reserve 1984-2013 US Army Retired

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US Secret Service, FBI, BATF, Local Law enforcment agencies, Diebold, Hamilton Pacific, Red Hawk Int., Chubb International, Bank of America, Wells Fargo Bank, Mechanics Bank, El Dorado Savings Bank, many Credit unions and smaller banks. McDonalds, Togos, BurgerKing, TacoBell, Carls Jr. FoodMaxx, SaveMart, Lucky's, Albertson's, Raley's, Safeway, NobHill, Bell Markets, PW Markets. Great America, Century Theatres, Cinemark Theatres, UA Cinemas, and many homeowners and small businesses. Provide warranty service for lock and safe manufactures. Service area is Northern California - Fresno to Oregon, including western Nevada

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