The Grenfell Tower fire occurred on 14 June 2017, killing 72 people. The pattern and speed of vertical and horizontal fire spread characterize this catastrophic event. Plentiful video and photographic data of the fire spread available has been carefully verified and concatenated into a database. The verified data have been superimposed on a projection of the Grenfell Tower in order to track the development of the fire. The surface that is unburnt, burning, or extinguished, as well as the presence of internal fire at any given location, is thus recorded for the duration of the fire. An analysis of the results showed that the initial vertical propagation can be divided into three phases. After the façade ignited at the fourth floor, vertical propagation over time is linear, with a vertical fire spread rate of around 3.5 m/min until the fire reached the sixth floor. Then fire propagation decelerated. Finally, fire spread accelerated with a power four dependence. The maximum vertical fire spread rate was around 8 m/min as the fire reached the crown at the top of the building. Horizontal spread proved to be greatest at the level of the crown (0.293 ± 0.005 m/min). There is a linear relationship between speed of horizontal fire spread and height. These correlations and observations yield important conclusions, and eight different hypotheses capable of explaining the global behaviour of the fire are suggested.

中文翻译：

---

格伦费尔大厦火灾的重建。第1部分：观察和确定工作假设的经验教训

2017年6月14日发生格伦菲尔铁塔大火，造成72人死亡。垂直和水平火势蔓延的方式和速度是这一灾难性事件的特征。大量可用的火势蔓延视频和照片数据已经过仔细验证，并连接到数据库中。已验证的数据已叠加在Grenfell塔的投影上，以便跟踪火灾的发展。因此，在火灾期间记录未燃烧，燃烧或熄灭的表面，以及在任何给定位置存在内部火灾。结果分析表明，初始垂直传播可以分为三个阶段。外立面在四楼点燃后，垂直传播随时间呈线性，垂直火势蔓延率约为3。5 m / min，直到大火到达六楼。然后，火势传播减速。最后，火势以四次方依存度加速蔓延。当大火到达建筑物顶部的顶部时，最大垂直火势蔓延速率约为8 m / min。事实证明，水平扩展在树冠水平最大（0.293±0.005 m / min）。在水平火势蔓延速度与高度之间存在线性关系。这些相关性和观察得出重要的结论，并提出了八种能够解释火灾整体行为的假说。事实证明，在树冠水平方向上最大的水平展宽（0.293±0.005 m / min）。在水平火势蔓延速度与高度之间存在线性关系。这些相关性和观察得出重要的结论，并提出了八种能够解释火灾整体行为的假说。事实证明，水平扩展在树冠水平最大（0.293±0.005 m / min）。在水平火势蔓延速度与高度之间存在线性关系。这些相关性和观察结果得出重要结论，并提出了八种能够解释火灾整体行为的假说。