Ballistic sliding bomb shelter door

 

American Safe Room is your complete design, engineer, and build solution for high pressure double leaf blast resistant doors


Plate steel or fabricated steel blast resistant doors
with engineer certified UFC-3-340-02 dynamic blast load calculations

Double leaf blast doorWe have supplied plate and fabricated steel single leaf blast doors for a variety of critical applications ranging from nuclear power plants to aerospace industry test cells, foundries, and military munitions bunkers. We work with our customers to ensure that our custom engineered product will meet their needs.

Our doors feature a wide range of proven hardware that can be scaled up or down to meet your requirements. Our high duty-cycle hinges and latches feature oil impregnated bronze sleeve bearings and stainless grease fittings. We've built double leaf doors up to 25 feet wide by 20 feet tall that weighed 27,000 pounds.

We can quickly and easily design doors for your unique triangular or bilinear dynamic blast load specifications. A triangular blast load is characterized by either the peak pressure (psi) and duration (ms), or by impulse (psi-ms) and either peak pressure or duration. A bilinear blast load is a combination of two triangular loads resulting from shock pressure and gas pressure.

We complete the initial design and engineering calculations in house and send them out to be reviewed and certified by a professional engineer. All initial design and engineering is done in house, then the design is reviewed by external professional engineers so that we can get stamps in all 50 states and Canada and more.

 

Concrete filled steel envelope doors
with engineer certified static blast load calculations

Double leaf blast doorOur concrete filled doors are the best solution for bomb shelters and safe rooms. They are legitimate blast doors, not ornamental "vault style" doors made from sheet metal with fancy paint jobs.

These doors are also very popular for industrial applications - even in low pressure environments. Compared to other manufacturer's 5 to 10 PSI doors, they cost less and have a significant margin of safety!

They have outstanding ballistic properties - UL 752, level 8 compliant (multiple 7.62 NATO ball) and the door leaves cannot be cut with a torch. Add to that our engineer certified 50 PSI blast load rating and you have the perfect bomb shelter door.

The standard construction is 5/16" steel skins with 5" of concrete fill. The door leaf envelope is filled after the door is mounted on the wall. Mount a 900 pound door and then fill it with concrete to put 2,300 pounds of mass between you and whatever is outside your shelter!


See our standard sizes, prices, and the technical manual in this column >>>

Hardware - hinges and latches

We manufacture a line of heavy duty door hardware that ensure you will have years of trouble-free operation. Our engineers select the hardware set based on the blast load requirements, the rebound response, and the door leaf weight.

Double leaf blast door hingesStandard duty hinges
These massive hinges are machined from one and a half inch shafts that capture oil impregnated bronze sleeve bearings that are press fit into steel blocks. They feature grease fittings for ongoing lubrication. The end blocks have a full strength continuous weld to the frame and the pins are stitch welded to the door leaf to spread the forces over a large area. We use these hinges on door leaves up to 2,200 pounds. They are rated for 60,000 pounds per hinge - and our hinges go up in strength from there:

 

Blasts door hinge close-upHeavy duty hinges
These hinges allow the door leaf to be removed from the frame for assembly or repair in the filed. They are machined from 2.375" 1018 cold rolled steel. Both the frame and door leaf have continuous full strength welds. They feature oil impregnated bronze sleeve bearings that have a flange that bears the thrust load.

We recess the stainless steel grease fitting into the bottom pin. The top pin has the capture bracket. The capture bracket in this picture is bolted on to the frame so the door leaf can be removed if needed. For high security applications, we weld the capture bracket in place.

See the video below for showing removal and reinstallation of a 6,500 pound 78" x 132" plate steel door leaf with four heavy duty hinges.

 

 

Blasts door hinge close-upExtreme duty hinges
We fabricate these hinges from ASTM A572 plate steel. They feature high load oil impregnated bronze alloy sleeve bearings and separate oil impregnated high load bronze alloy thrust bearings. The pins are machined from two inch 1018 cold rolled steel and are welded in place after the door leaves are installed on the embedded frame. These hinges are suitable for extremely large and heavy door leaves.

See the video below showing a 12.5 foot by 20 foot 7 ton door leaf with these hinges being function tested in our fabrication shop:

 

Cam latch close-upCam latches
The cam latches are rotating handles on the inside of the door leaf that engage a cam welded on the frame. They operate in opposite directions in case the door is subject to violent movements by a detonation - one may loosen, but the other one will tighten, holding the door in place.

As you turn them, they draw the door leaf into the frame, compressing the door seal.

This picture shows the latch in the closed (latched) position. Note the bracket on the door leaf above the latch that allows you to lock your latches in the open position with a paddle lock. The hole in the bracket correspond with the hole in the cam latch handle.

Blast door cam latchesThis picture shows the latches in the open (unlatched) position. They are positions over the brackets. Most machinery and large tools have a "lock out" function for maintenance. This duplicates that function in case you have to give someone access to your shelter who may try to lock you out. We incorporated this feature on all of our blast doors after a customer with a teenager inquired about a way to ensure he was not locked out of his shelter.

Blast door cam latchesOn doors that are too tall to reach the top latches, we use gear driven latches. This is a 13 foot wide by 11 foot tall plate steel double leaf door with gear latches. Each leaf has a rotating handle that throws a shear plate in two directions to securely latch the door shut.

Here is a video showing the operation of these latches. Note that each door leaf weighs 6,500 pounds, but they are easily moved by one person due to the oil impregnated bronze sleeve bearings and stainless steel grease fittings.


 

Double leaf blast door with outside operatorsOutside operators
On doors that require access from both sides, we install outside cam latch operators.

On the seated side of the door leaf, they operate just like our standard cam latches. One the unseated side, they have a handle that is on a shaft that goes through the door leaf and rotates the cam latch inside. We machine a steel barrel for the shaft to ride in. Each end of that barrel has an oil impregnated bronze bushing and there is a stainless steel grease fitting on the seated side. These outside operators are not suitable for bomb shelters or safe rooms, but they are quite popular with our industrial customers.



Professional engineer certified blast load calculations

Plate steel doors
Plate steel doors are fabricated from a single piece of steel. The hinges and latches are welded directly to the door leaf plate. On doors that require less than one inch of plate, we fabricate a frame to hold the plate flat out of structural steel tubing.

Fabricated steel doors
Very large doors or doors that have extreme blast loads can require a plate thickness that becomes weight and cost prohibitive. We engineer door leaves that are fabricated from wide flange beams with a steel skin on each side.

Calculations for plate and fabricated steel doors
Because the plate thickness and fabrication of these doors are driven by the blast load specifications, we engineer these doors to your specifications. We will quote the engineering and calculations separately from the doors. Contact our sales department to start the process.

See our custom blast door page for a gallery of doors that we have engineered and built.

Certification for single leaf blast doorConcrete filled door leaves
We have standard sizes and thicknesses for our concrete filled doors.
These doors are certified by a professional engineer to withstand a 50 PSI (3 bar) blast load in the seated condition and 14.5 PSI (1 bar) rebound load in the unseated condition.

Sealing it all up - the door seal and threshold style

Blast door seal close-upCompression seal
These doors features a synthetic rubber seal between the door and the frame allowing for the use of a positive pressure NBC filtration system inside the shelter. The inside cam latches draw the door into the seal as they are rotated. This puts the seal under compression between the door leaf and the frame. The strict tolerances we hold allow us to use a closed cell EPDM foam seal - not the bulb (automotive type) seal commonly used when manufacturers can't hold the tolerance necessary for a solid seal. This seal is expertly applied without stretching it and the corners are cleanly chamfered to seal out airborne toxins.

 

Blast door seal close-upSteel on steel
We stitch weld a piece of flat bar onto the edge of the door leaf to ensure the door seal does not get over-compressed. This steel on steel dead stop keeps the door seal within the manufacturer's specifications for compression.

It's the attention to details like this that keeps our doors going for years in high duty-cycle industrial applications.

 

Fire rated blast door sealFire rated door seal
As an option, you can get a second, fire rated seal applied outside of the primary seal.

It is a 1/2” wide bulb seal that would have to fail before the main seal is compromised by a thermal event.

Tested in accordance with NFPA (National Fire Protection Association) standards 105 and 252, this seal also meet ASTM E283, E90, and E413. UL classified for use on hollow metal and steel-covered composite-style fire doors rated up to and including three hours. Meets UL 10B, UL 10C, and UL 1784.

 

Flat threshold inward swinging blast doorThreshold options
Double leaf doors carry the blast load from top to bottom. This means the threshold is required to hold up to one third of the force against the door leaves. It is preferable to have a poured concrete threshold that matches the strength of the wall, but we have built double leaf blast doors that had an integral steel threshold.

12 foot high double leaf blast doorFlat thresholds
Some projects demand that there is no concrete or steel threshold. For these doors, we drop pins into embedded sockets.

This is a 12 foot high double leaf blast door with no top frame rail and a flat threshold. It is used in a blast containment room in a foundry where crucibles can be either rolled over the flat threshold or hoisted through the open top with a bridge crane.

Flat threshold inward swinging blast doorScaling up the flat threshold
This is a 25 foot wide by 20 foot high double leaf blast door for a test cell.

We engineered shear pins that drop into embedded sockets in the floor. Each door leaf has eight two inch pins machined from 1018 cold rolled steel. They are held in place by bronze alloy sleeve bearings that are pressed into four and half inch steel barrels that are in turn secured by three-quarter inch steel stirrups.

The total load on this double leaf blast door is over a half million pounds.

 

Door, ready to sellSizes - standard and custom
This door comes in two standard sizes - and customs sizes can be built. The standard sizes are 72 inches wide by 80 inches tall and 96 inches wide by 80 inches tall. The free opening when installed is nominally one half inch under the rated size. Please see the manual for more information. We have built many custom sized doors. If you have an existing opening that needs a blast door, please contact us.

 

We've placed a lot of these doors in industrial applications: chemical plants, foundries, ordnance storage magazines, ordnance testing ranges, refuge chambers, and even a rhinoceros enclosure at a zoo. If you have an application that needs to protect from, or to contain a detonation, please contact our Sales Manager at 541-459-1806 or sales@AmericanSafeRoom.com

Price, availability, and manual

Complete price sheet of all items (PDF)

      Item Double leaf blast door
      Model number ASR-DBL-BD-72-80
      Price each $8,350.00
        plus options and shipping
      Status Special order item
         
         
      Item Double leaf blast door
      Model number ASR-DBL-BD-96-80
      Price each $8,850.00
        plus options and shipping
      Status Special order item
         

     

      Options


      see the manual for more information

      Option Outside operators
      Price $1,250.00 (USD)
         
      Option Assault resistant cam latches
      Price $1,250.00 (USD)
         
      Option Hasp assembly
      Price $225.00 (USD)
         
      Option Wide angle viewers (2)
      Price $150.00 (USD)
         
      Option Differential pressure gauge
      Price $325.00 (USD)
         
      Option Pour in place frame
      Price $1,800.00 (USD)
         
      Option Extra fire rated seal
      Price $350.00 (USD)
         
      Option Custom sized door
      Price quoted upon request
         
         

      Telephone 541-459-1806 or e-mail
      sales@AmericanSafeRoom.com
      with questions or orders

       

       

      ASR-100-AV-NBC Safe Cell manual
      Installation and operation manual

      Get Adobe Reader

       

       

       

      Click to enlarge

       

      Two double leaf doors ready to ship

       

      Fabricating a double leaf blast door

       

      Inward swinging double door

       

      Double door leaf on a bridge crane