> Later on Monday morning, a second heavy tugboat arrives to pull the ship off completely. In addition, water will be sprayed under the ship with great force to wash away sand and clay. If it is not possible to clear the front of the ship in this way, containers may have to be unloaded from the front of the ship.
I fail to understand why they didn't/don't use the tugboats to wash the water away. Even small boats can cause a lot of scour with their bow thrusters along a vertical quay wall (which the Ever Given is in a way). The erosive power of a 16MW engine is really something to not be underestimated.
>I fail to understand why they didn't/don't use the tugboats to wash the water away. Even small boats can cause a lot of scour with their bow thrusters
If the following video explanation is accurate, a tugboat's turbulence can't scour down to ~50 ft depth of sand:
https://youtu.be/zBvFuq7Mkzs?t=1m00s
I think the confusion we have with all these news reports is that we really don't have a definitive visualization or geometry of how its actually stuck in the sand that's accurate/authoritative. A bunch of overhead drone shots don't really reveal to us the true extent of the problem that's hidden underneath the waterline.
We just see words about tugboats arriving and water spraying so our instinct is to simplify the problem to "I don't understand why they can't just do <X>?!?"
1. They can’t manoeuvre tugs into the right location due to the aforementioned silt and dirt the Ever Given is stuck on/dug up.
2. Tug bow trusters are difficult to aim. Plus how do you hold them steady? They can only fire in one direction at a time, so you have no ability to create a reaction thrust to prevent the tug from moving.
3. Tug thrusters don’t enjoy ingesting huge amounts silt and earth when they’re operating. Which invariably will happen if they’re close enough to banks to have a useful erosive effect.
There’s been like 2 dudes out there with an excavator for a week. Absolutely nothing about this has made any sense. Based on the amount of revenue lost due to this blockage you’d think every military on the earth would have descended there.
tda|5 years ago
jasode|5 years ago
If the following video explanation is accurate, a tugboat's turbulence can't scour down to ~50 ft depth of sand: https://youtu.be/zBvFuq7Mkzs?t=1m00s
I think the confusion we have with all these news reports is that we really don't have a definitive visualization or geometry of how its actually stuck in the sand that's accurate/authoritative. A bunch of overhead drone shots don't really reveal to us the true extent of the problem that's hidden underneath the waterline.
We just see words about tugboats arriving and water spraying so our instinct is to simplify the problem to "I don't understand why they can't just do <X>?!?"
EDIT to add informative deep link of how the ship got stuck mentioned by another thread: https://youtu.be/5iyn2q6s1Sk?t=4m28s
avianlyric|5 years ago
1. They can’t manoeuvre tugs into the right location due to the aforementioned silt and dirt the Ever Given is stuck on/dug up.
2. Tug bow trusters are difficult to aim. Plus how do you hold them steady? They can only fire in one direction at a time, so you have no ability to create a reaction thrust to prevent the tug from moving.
3. Tug thrusters don’t enjoy ingesting huge amounts silt and earth when they’re operating. Which invariably will happen if they’re close enough to banks to have a useful erosive effect.
itomato|5 years ago
whalesalad|5 years ago