關於建築...

呢個問題我細個見人地起樓都有唸過
今日見到有人問, 我專登去搵呢個答案... 我自己都想知


起樓用的起重機, 一般係 T 形

先講下 T 字既 橫樑 係點裝上:
果一橫, 係透過另一部流動起重機一段一段裝上的

T 字既 一直 (腳架) 係點裝上: (即係點樣可以提升起重機既高度)
其實, 起重機係自己幫自己增高的
方法是 : 利用油壓積將腳架最高的一段分離並升高約 6 米
(腳架本身是一段一段的, 每段 6 米高)
咁樣, T 字中的 橫 與 直 之間就會出現了 6 米的空間
之後利用起重機, 吊一段新既腳架去呢個空間
最後工人為起重機裝上一段新腳架
完成後, 起重機就增高左 6 米

重複步驟, 起重機可不斷升高

至於拆下來... 就是將上面既步驟倒轉黎做

Get the tower crane supplier to put it there.
They would install a temporary lifting crane to install and remove the tower crane.
You can approach some tower crane company to ask for details. e.g. Manta.

This is a tower crane (天秤), which it carries the building materials up/down at high level of the construction site when the concrete slab or wall making.
The tower crane uses ropes and hook with the hoisting mechanism and counterweight for balancing to lift up/down the materials to construction floor, it was monitored closely by Labour Dept.

I'll give you the link rather than copying the full text in here!

http://science.howstuffworks.com/tower-crane.htm

It gives you info on how the tower crane is constructed and some general info about the crane itself.

Hope this helps!

2006-10-15 14:09:22 補充：
hey guys, i think he's trying to ask how the tower crane is constructed, not what it is used for!

當然是由樓梯上落!!