A typical wood frame house of modern construction is securely bolted to its foundation. Mobile homes, on the other hand, simply sit on pedestals or stands, making them particularly vulnerable to earthquakes.

During the 1978 earthquake 324 mobile homes were damaged in Goleta. Many of these mobile homes were knocked from their pedestals, rupturing gas, water, and electrical connections. In the Santa Barbara West Mobile Home Park in Winchester Canyon, over 35% of 147 mobile homes were knocked off their pedestals. Many of the pedestals ended up sticking through the floors of the mobile homes. One mobile home was destroyed by fire in a gas leak. In contrast, conventional homes in Goleta were relatively unscathed, suffering only cracked plaster, broken glass, and loosened plumbing.

In a 1980 study by Steinbrugge et al., it was found that in high intensity earthquakes mobile homes suffer damage double wood frame houses, and in moderate intensity earthquakes, the difference is even greater, mobile homes suffering damage at a rate of five times a wood frame houses. Much of this is due to the insecure placement of the mobile homes on loose pedestals.

Sources

• K. V. Steinbrugge, E. E. Schader, S. T. Algermissen (1980). Earthquake damage to mobile homes in California, California Geology, v. 33, 225-232.
• R. K. Miller, S. F. Felszeghy, Engineering features of the Santa Barbara earthquake of August 13, 1978, Santa Barbara, CA.

Photographs

View of mobile home #1 (38 kb)

View of mobile home #2 (41 kb)