One winter afternoon, the sun shone warmly enough to make the cold almost forgettable. Several high school boys stopped by their friend Yonasan’s house after class, unzipped their coats, and headed outside.
In the backyard was a wide hammock stretched between two sturdy posts.
At once, three boys climbed together onto the hammock. The fabric stretched taut and dipped low but continued to hold.
“I hope that the fabric is strong,” one of them said hesitantly. “So far, it’s holding us.”
They rocked gently, chatting about school and plans for the evening.
A few minutes later, Dovid wandered over. “Looks like fun,” he said. Without much thought, he climbed on as well, squeezing in at the edge.
“Careful!” Shimon muttered. The hammock groaned, stretching tighter than before – but it still held.
Five minutes passed. Then without warning, there was a loud crack. The hammock snapped, sending all four boys tumbling onto the grass.
Yonasan ran outside. “What happened to my hammock?!” he asked, staring at the torn ropes and fabric.
The boys picked themselves up, brushing off dirt. The debate began almost immediately.
Shimon spoke up. “The hammock was fine when we were on it until Dovid joined,” he said. “He pushed it over the limit – it’s his fault.”
Dovid shook his head. “That’s not fair. The three of you already strained it,” he argued. “We all contributed to breaking it.”
“But it didn’t break until you came,” Shimon insisted.
“If you thought it was overloaded, though,” Dovid shot back, “why didn’t you get off when I joined?”
“Let’s ask Rabbi Dayan,” Yonasan said. Together, they posed the question:
“Who is liable for the broken hammock?”
“The Gemara (B.K. 10b) addresses the case of several people who sat on a bench that broke,” replied Rabbi Dayan. “It differentiates between various cases; the Rishonim and poskim further dispute details of these cases.
“In the simplest case, when they sat down simultaneously and exceeded the capacity, they all bear liability (C.M. 381:1).
However, if they did not exceed the capacity but the bench still broke, some exempt them based on the principle of meisah machamas melacha, even if they did not have explicit permission to sit on it, because people typically allow others to sit on their benches (Rema 381:1; Pischei Choshen, Nezikin 10:30-31[62]).
In a case in which they sat down one after another, if the bench was capable of supporting the initial people but the final person exceeded the bench’s capacity and it broke immediately, then the final person to sit down clearly broke it and is liable.
Even if it did not break immediately, Rema – following the Nimukei Yosef, Rosh, and Tur – maintains that because the bench could support the initial people, only the final person who exceeded the capacity is liable, although the initial people did not get up after he sat down (Aruch HaShulchan 381:2).
However, some Acharonim understand from Rashi that even if the bench did not break immediately, the initial people also share in the liability, because they had no more right to use the bench than did the final person. Once he sat down, they should have realized that they jointly exceeded the bench’s capacity and should have gotten up. Only if the last person prevents the others from getting up does he bear lone liability (Gra and Aruch HaShulchan 381:1; see Pischei Choshen, Nezikin 10:30-31[64]).
In a case in which the initial people already exceeded the bench’s capacity and it was destined to break at some point, but the final person made it break faster – they are all liable if they remained sitting until it broke after a short time, because they all contributed to breaking it. If the bench broke before the others could get up, though, or if the final person prevented them from getting up, he alone is liable (Rema 381:1).
“Our case of the hammock is similar,” concluded Rabbi Dayan, “depending on the details of the case. If the hammock could support the initial three boys, but the fourth exceeded its capacity, according to Rema only he is liable. If the hammock was already strained beyond capacity and destined to snap, though, but the boys remained on it – then they are all liable.”
Verdict: The person who exceeded the bench’s or hammock’s capacity is liable. If several people sat down and exceeded its capacity, they are all liable, even if the final person made it break faster than it would have otherwise.