What are two differences between the new fort and the shelters on the beach in Lord of the Flies?
The shelters on the beach were meant to be a safe place for everyone, a kind of centralized location near the assembly place that could be established as "home". Yet after the first couple hours, no one would help Simon and Ralph build. As a result, the only shelters are poorly constructed and prone to collapsing.
Ralph turned to the shelter and lifted a branch with a whole tiling of leaves. The leaves came apart and fluttered down. Simon’s contrite face appeared in the hole.
Ralph surveyed the wreck with distaste.
“Never get it done.”
He flung himself down at Jack’s feet. Simon remained, looking out of the hole in the shelter. Once down, Ralph explained.
“Been working for days now. And look!”
Two shelters were in position, but shaky. This one was a ruin.
The shelters represent the tenuous bonds of society: the fragile connections holding the boys together as a group. Of course, even in their building the shelters cannot bring the boys together, which could symbolize the weakness of civilization in the face of savagery.
The fort, on the other hand,is in a strategic position of power and exclusion. High on the cliff of "Castle Rock", Jack has complete control over his location and his tribe. Here, he rules with an iron fist, and those who don't complete their jobs are beaten (some, like the unfortunate Wilfred, for seemingly no reason). So this location represents the power of savagery and violence in the human race, and the ultimate power of authoritarian rule. The fort's location was specially chosen so that the tribe could ambush anyone approaching. In contrast to the open, accessible shelters, the fort is closed off and difficult to get to.