Hello! I've been searching through the forum and found many threads about beam sizing, but not really any where large point loads are specifically discussed. I apologize in advance if I've missed something.
So, what I want to do.
I have a pile of logs. They are placed on a frame that is 4000 mm long, 2000 mm wide, and 500 mm high. The logs are 3500 mm long and lay across the frame, sticking out about 750 mm on each side. The frame is full in length, meaning the log pile fills the 4000 mm and reaches just over 2000 mm high from the frame at its peak.
The largest logs are 800 mm in diameter, but most are about 400-500 mm. Calculating the weight of the largest log gives a maximum of 1500 kg.
I want a lifting winch with a timber clamp that picks up one log at a time and moves it to a saw where I cut it into planks.
This is outdoors, no roof. I have 3-phase electricity on site via a construction central.
I'm considering building a small roof around the saw for rain protection, etc., and a small storage room, but we're not talking about something that can carry that type of load.
My question is what I can use to support the lifting winch. It needs to be able to move along the entire pile of logs (4000 mm) and at least 2000 mm more to come over the saw’s log shelf and allow 1000 mm in front of the saw for a cart to receive the cut planks. So, 6000 mm long.
My thought is to have supports on each side and a long (6000 mm) beam. But what kind of beam? Steel I-beam is common, but what type of beam do I need to handle a 1500 kg dynamic point load on a 6000 mm span? Is steel the best option? What about glulam? Or maybe a "box beam" made of wooden studs? In that case, what size? Is it an option to let the winch hang from a cable between two pillars?
I've also considered if I can shorten the 6000 mm by adding more supports. In that case, those supports would need enough spacing for the logs to pass through (possibly rotating them a bit when lifted). But the question then is if it's truly economical, as many supports would be needed to change the required beam sizing, and considering point loads, each support would need to handle max point load.
Advice? Thoughts?
So, what I want to do.
I have a pile of logs. They are placed on a frame that is 4000 mm long, 2000 mm wide, and 500 mm high. The logs are 3500 mm long and lay across the frame, sticking out about 750 mm on each side. The frame is full in length, meaning the log pile fills the 4000 mm and reaches just over 2000 mm high from the frame at its peak.
The largest logs are 800 mm in diameter, but most are about 400-500 mm. Calculating the weight of the largest log gives a maximum of 1500 kg.
I want a lifting winch with a timber clamp that picks up one log at a time and moves it to a saw where I cut it into planks.
This is outdoors, no roof. I have 3-phase electricity on site via a construction central.
I'm considering building a small roof around the saw for rain protection, etc., and a small storage room, but we're not talking about something that can carry that type of load.
My question is what I can use to support the lifting winch. It needs to be able to move along the entire pile of logs (4000 mm) and at least 2000 mm more to come over the saw’s log shelf and allow 1000 mm in front of the saw for a cart to receive the cut planks. So, 6000 mm long.
My thought is to have supports on each side and a long (6000 mm) beam. But what kind of beam? Steel I-beam is common, but what type of beam do I need to handle a 1500 kg dynamic point load on a 6000 mm span? Is steel the best option? What about glulam? Or maybe a "box beam" made of wooden studs? In that case, what size? Is it an option to let the winch hang from a cable between two pillars?
I've also considered if I can shorten the 6000 mm by adding more supports. In that case, those supports would need enough spacing for the logs to pass through (possibly rotating them a bit when lifted). But the question then is if it's truly economical, as many supports would be needed to change the required beam sizing, and considering point loads, each support would need to handle max point load.
Advice? Thoughts?
In my eyes, it seems like you need some form of telfer? Viewing it as a static problem, it suffices to design for a point load at the center of the beam, as the deflection will be greatest there. When the point load is then moved closer to the beam's support ends, the deflection will decrease. In steel, an HEA 160 beam should suffice. In glulam, 90x315 mm. Then it's important to stabilize it in all directions.
Thanks!J justusandersson said:
Yes, that's what I was thinking, just wasn't clear on the dimensions. Glulam 90x315x6000 mm costs about 1700 SEK at Byggmax, it's actually not that bad. The question is if I can find a trolley that can handle a 315 mm high beam, but in the worst case, I can create "shelves" with 45x95 mm outside the glulam beam and mount the trolley there.