Dock shelters are enclosures that seal the perimeter of the trailer and form a seal by applying pressure against the sides of the trailer with industrial fabric curtains fitted with fiberglass stays. The seal at the top is created with a curtain designed to reach down to the trailer. This header curtain may be weighted or simply constructed of fabric, and may be self-adjusting or require pull-rope adjustment depending on the model. The side curtains may or may not be equipped with features to seal around trailer door hinge gaps. As a category, dock shelters historically weren’t able to provide as tight of a seal as foam dock seals, although the newest models are equipped with features that allow them to match the sealing effectiveness of foam seals.
The benefits of dock shelters in general are numerous. By design they are able to fit larger dock door openings and service a wide variety of trailer heights and styles. And, they are less subject to damage from daily wear and tear as they are not designed to be compressed by the trailer and therefore are not subject to extreme pressure in normal use.
The disadvantages of dock shelters relative to foam seals are that some models provide substantially less sealing efficiency, especially when trailer door hinge gaps are left unsealed. Also, if shelter side frames are constructed of non-impactable materials, they can be severely damaged upon trailer impact, requiring costly repair or replacement. As a category, dock shelters are generally more expensive than dock seals. Price difference between models is based primarily on sealing effectiveness: Price reflects the number and type of features included to provide tight sealing along trailer sides, upper corners, and across the top. Price differential between models also reflects differences in side frame construction and related ability to withstand damage from the impact of trailers backing in off center.