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Crash Testing and Evaluation of Multiple Mailbox Supports for Use with Locking Architectural Mailboxes

Chiara Silvestri DobrovolnyRoger P. BlighWanda L. Menges

出版	Texas A & M Transportation Institute, 2017
URL	http://books.google.com.hk/books?id=LB-FswEACAAJ&hl=&source=gbs_api

註釋Some homeowners and businesses are becoming increasingly concerned about mail-identity theft. Consequently, there is a growing demand for the use of locking mailboxes for theft deterrence and vandal resistance. There are a number of mailbox products on the market that offer enhanced security for mail and small parcels. They typically feature an upper hopper for incoming mail, and a lower lockable compartment for mail retrieval. These lockable mailboxes are significantly larger and can be 4 to 5 times heavier than standard lightweight mailboxes, which are approximately 5 in ches wide, 6 inches tall, and 19 inches long, and weigh less than 5 lb. Therefore, TxDOT requested evaluation of their crashworthiness before permitting their use on the state highway system. Under TxDOT Project 9-1002-12, crash tests were performed following Manual for Assessing Safety Hardware (MASH) guidelines and procedures to assess the impact performance of lockable, secure mailboxes in both single and multiple-mount configurations. Testing of the larger (15 inches tall, 11.5 inches wide, and 18 inches deep), heavier (approximately 23 lb) locking mailboxes on multiple-mount support posts resulted in failure due to vehicle windshield deformation and intrusion. Under this project, crashworthiness of proposed designs for multiple-mailbox supports used with a combination of lockable and standard mailboxes was evaluated. This evaluation was performed to determine if TxDOT can permit their use on the state highway system. The crash tests were performed following the latest MASH guidelines and evaluation criteria. Two proposed designs were evaluated through full-scale crash testing: 1) 11-gauge (0.125-inch) steel tube multiple-mount support with 4-inch embedment. 2) 16-gauge (0.0625-inch) steel tube multiple-mount support with inclusion of ơ-inch -diameter wire rope and with 6-inch embedment. Both systems satisfied all required MASH evaluation criteria at low and high impact speeds using an 1100C passenger car. Implementation of these designs can be accomplished through appropriate revision of the TxDOT Mailbox Mounting and Spacing standard (MB-11(1) by the Maintenance Division.