New Day Tornado Shelter Specifications

Shelter Overview

The New Day Tornado Shelter is an above-ground, cylindrical steel shelter engineered for extreme tornado conditions. Its domed top design and reinforced walls provide superior wind, impact, and

load resistance.

Dimensions & Materials

• Diameter: 42 inches
• Height: 80 inches
• Wall Thickness: 3/8" SA-455 carbon steel
• Dome Thickness: 1/4" SA-455 carbon steel
• Door Material: A36 cold rolled steel
• Weight: 1,100 lbs

Anchoring System

• Anchors: (9) 1/2" concrete screws
• Embed Depth: 3.5 inches
• Engineered to exceed FEMA P-361 requirements

Wind & Impact Resistance

• Wind rated to 318 mph (EF5)
• Projectile impact resistance >100 mph (15-lb 2x4)
• Drag Coefficient (Cd): 0.5 - 0.6
• Compliant with FEMA P-361 and ICC 500

--- Calculations ---

• Wind Speed: 318 mph (EF5 tornado)
• Air Density: 0.0023769 slugs/ft³
• Drag Coefficient (Cd): 0.5 - 0.6
• Projected Area (cylinder): ~9.6 sq ft
• Wind Pressure (q) = 0.00256 × V² = 0.00256 × (318)² ~ 259.2 psf
• Total Wind Force ~ Pressure × Area = 259.2 psf × 9.6 ft² ~ 2,486 lbs
• The shelter was designed with a 3.0 safety factor to resist this force

Load Capacity

• Domed Top Area: ~9.6 sq ft
• Load Resistance: ~16,300 lbs (uniform load)
• Material Yield Strength: ~50,000 psi

Why Choose New Day?

• Premium SA-455 carbon steel
• Pressure-vessel-grade engineering
• Better airflow and load dispersion
• Compact, safe, and secure

What Does 3/8" SA-455 Steel Stop?

According to steel penetration data and military testing:

• 3/8" of high-strength steel can stop:
• A 2×4 at 150+ mph
• A 20-lb steel pipe at 80–100 mph
• A 100-lb log (blunt object) at ~60–70 mph
• It would take over 5,000–6,000 ft-lbs to begin denting or deforming this steel, and well over 10,000 ft-lbs for potential rupture (very rare)

New Day Tornado Shelter Specs

There are several aspects of the patented design that make a New Day Tornado Shelter different from every other kind of storm shelter. The domed design makes it a stronger storm shelter that's more space efficient!