Transport for London inconsistently labels emergency spiral staircases with vastly different step counts—including Covent Garden (193 steps), Russell Square (175 steps), and Hampstead (320 steps)—as identically equivalent to a 15-storey building. (4:28)
Physical measurements across all surveyed stations reveal an identical riser height of 17 centimetres per step, allowing precise mathematical conversions against the standard architectural storey height of roughly 304 centimetres (10 feet). (0:01)
Real-world calculations demonstrate that none of the staircases actually equal 15 storeys: Covent Garden equals roughly 11 floors, Russell Square equals 10, and Hampstead reaches nearly 18 floors. (8:06)
Detailed notes
## Background
Published on YouTube by Geoff Marshall on January 16, 2018, this video addresses viewer confusion sparked by an earlier video at Tufnell Park where climbing 110 steps was described as climbing a 15-storey building. Marshall sets out to explain the inside joke and running gag behind London Underground's notably inaccurate staircase warning signs.
## TL;DR
Following comments on an earlier video, Geoff Marshall investigates a recurring Transport for London oddity where spiral staircases of vastly different lengths are all labeled as the equivalent of a 15-storey building. Visiting Covent Garden (193 steps), Russell Square (175 steps), and Hampstead (320 steps), he measures step risers at 17 centimetres across all three locations and finds the exact same 15-storey claim displayed on their signage. Back home, he crunches the numbers against standard 304-centimetre building storeys and relative ratios, proving mathematically how arbitrary the signage is. Rather than demanding accuracy, Geoff embraces the comedic absurdity and jokingly urges TfL to preserve and expand the running gag across the network.
## Atmosphere & style
The video carries an energetic, playful, and geeky tone that feels like an urban micro-investigation blended with stand-up transit comedy. Armed with a tape measure in tiled spiral stairwells, Geoff brings an infectious enthusiasm and self-deprecating wit to what could otherwise be dry architectural arithmetic. The transition from bustling Underground stations to cozy home calculations gives the video an endearing, bespoke charm rooted in genuine affection for London's quirky infrastructure.
## Bulletin
- [04:28](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=268s) Transport for London inconsistently labels emergency spiral staircases with vastly different step counts—including Covent Garden (193 steps), Russell Square (175 steps), and Hampstead (320 steps)—as identically equivalent to a 15-storey building.
- [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) Physical measurements across all surveyed stations reveal an identical riser height of 17 centimetres per step, allowing precise mathematical conversions against the standard architectural storey height of roughly 304 centimetres (10 feet).
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) Real-world calculations demonstrate that none of the staircases actually equal 15 storeys: Covent Garden equals roughly 11 floors, Russell Square equals 10, and Hampstead reaches nearly 18 floors.
## Key takeaways
- [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) Geoff Marshall clarifies an internal running gag sparked by viewer confusion over a previous video claiming 110 steps at Tufnell Park equated to a 15-storey building.
- [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) Covent Garden serves as the original source of the joke, where station signage warns that its 193-step spiral staircase equals a 15-storey building.
- [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) Physical measurements confirm that the riser height for spiral stair steps across the visited London Underground stations is consistently 17 centimetres.
- [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) Standard architectural practice considers an average building storey to be approximately 10 feet or 304 centimetres high.
- [04:28](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=268s) Russell Square station features a 175-step staircase that active signage also describes as equivalent to a 15-storey building.
- [04:28](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=268s) Hampstead possesses the deepest underground station staircase on the network at 320 steps, yet official signage still describes it as equal to a 15-storey building.
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) Treating Covent Garden's 193 steps as a 15-storey baseline yields roughly 12.8 steps per floor, which would make Hampstead an exact 25-floor equivalent.
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) Applying real architectural dimensions shows Covent Garden's 193 steps actually equate to about 10.7 storeys (roughly 11 floors).
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) Architectural calculations show Russell Square's 175 steps measure roughly 9.7 storeys (about 10 floors).
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) Architectural calculations show Hampstead's 320 steps measure roughly 17.8 storeys (about 18 floors), far exceeding the 15-storey claim.
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) The mathematical absurdity of London Underground's universal 15-storey designation forms a core routine in Geoff Marshall's Tubespotting comedy show.
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) Geoff jokingly urges Transport for London never to correct the posters and proposes expanding the 15-storey gag to shorter staircases like Chalk Farm's 54 steps.
## Detailed walkthrough
### [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) The Tufnell Park Confusion and Covent Garden
Geoff Marshall begins at a sunny Green Park tube station, getting ready to board the Piccadilly line on an explanatory mission. In a previous video filmed at Tufnell Park, Geoff had walked up the stairs and included a caption stating the climb was the equivalent of a fifteen-storey building. Viewers quickly pushed back in the comments, pointing out that 110 steps could not possibly equal fifteen floors. Acknowledging that the confusion arose because he failed to explain an inside running gag, Geoff sets out to visit the origin point of the joke: Covent Garden station.
Covent Garden is a classic 1906 Leslie Green station featuring lifts and an emergency spiral staircase. Station signage prominently warns passengers that the spiral staircase has 193 steps, describing it as the equivalent of a 15-storey building. Geoff climbs the staircase to count and measure the steps. During the ascent, he muses about an urban legend regarding the origin of the word "storey"—allegedly stemming from historical buildings where readable stories were painted or displayed on each level so climbers had something to read as they progressed upward. At the top, Geoff reveals that he brought along a tape measure; measuring the step height reveals that each riser is exactly 17 centimetres. Turning to standard architectural dimensions, an average building floor is roughly 10 feet high, which translates to approximately 304 centimetres.
- Covent Garden step count: 193 steps.
- Measured riser height: 17 cm per step.
- Standard architectural storey height: 10 feet (~304 cm).
- Geoff admits his oversight: “And it's kinda my fault for not explaining the joke, so... i need to explain the joke but i also need to go to the source of that joke, the original fifteen-storey building which is Covent Garden!”
---
[04:28](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=268s) Investigating Russell Square and Hampstead
Continuing his field investigation along the Piccadilly line, Geoff heads to Russell Square. Russell Square is another Leslie Green-designed station, notable for its distinctive oxblood tiles, semi-circular arches, and the unused flat rooftop space originally reserved for commercial building extensions. Geoff walks up its spiral staircase of 175 steps, measuring the depth of the risers at the exact same 17 centimetres. Although he initially believes the old warning posters are gone—showing older photographic evidence on screen—he checks the top of the stairs when heading back down and discovers that active signage still asserts that the 175 steps equal a 15-storey building.
Geoff then transfers at Leicester Square from the Piccadilly line to the Northern line to reach the ultimate test case: Hampstead. Hampstead is the deepest underground station staircase on the entire network, plunging down 320 steps. Despite having vastly more steps than Covent Garden or Russell Square, the warning signage at Hampstead still boldly claims that climbing its staircase is the equivalent of a 15-storey building. Geoff measures the steps at Hampstead and finds that they, too, are 17 centimetres each. With three completely different staircases of 193, 175, and 320 steps all officially designated as 15 storeys, Geoff heads home to crunch the numbers.
- Russell Square step count: 175 steps (measured at 17 cm each).
- Hampstead step count: 320 steps (the deepest staircase on the network, measured at 17 cm each).
- Official London Underground signage at all three stations claims the staircases equal a 15-storey building.
---
[08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) The Maths and the "All Stations Have 15 Floors" Theory
Back home in the evening, Geoff sits down to break down the mathematics behind the absurdity, which forms a core routine in his *Tubespotting* stand-up comedy show. He notes that Transport for London seems to arbitrarily label any spiral staircase as a 15-storey building regardless of the actual height. To prove how incorrect the signage is, Geoff performs two separate mathematical breakdowns:
```mermaid
flowchart TD
accTitle: Two Methods for Calculating Tube Station Floor Equivalents
accDescr: Diagram illustrating Method 1 based on Covent Garden as a control versus Method 2 based on real-world architectural measurements.
subgraph M2["Method 2: Architectural Reality (17 cm step / 304 cm floor)"]
CG2["Covent Garden: 193 × 17 cm = 3,281 cm / 304 cm ≈ 10.7 (11 floors)"]
RS2["Russell Square: 175 × 17 cm = 2,975 cm / 304 cm ≈ 9.7 (10 floors)"]
HA2["Hampstead: 320 × 17 cm = 5,440 cm / 304 cm ≈ 17.8 (18 floors)"]
end
```
In the first approach, Geoff treats Covent Garden's 193 steps as the experimental control baseline for 15 storeys, which yields roughly 12.8 steps per floor (193 ÷ 15 = 12.86). Applying this ratio to Russell Square gives approximately 13.6 floors (rounded to 13), while applying it to Hampstead's 320 steps divides out cleanly to an exact 25 floors without any remainder.
In the second approach, Geoff applies real-world architectural measurements: multiplying each station's step count by the 17 cm riser depth to find the total height in centimetres, then dividing by the standard 304 cm storey height:
- **Covent Garden:** 193 steps × 17 cm = 3,281 cm. Divided by 304 cm, this equals roughly 10.7 floors (about 11 storeys).
- **Russell Square:** 175 steps × 17 cm = 2,975 cm. Divided by 304 cm, this equals roughly 9.7 floors (about 10 storeys).
- **Hampstead:** 320 steps × 17 cm = 5,440 cm. Divided by 304 cm, this equals roughly 17.8 floors (about 18 storeys).
Geoff concludes by affectionately pleading with London Underground not to rectify the posters because the absurdity is too amusing. He jokingly suggests they should expand the running gag across the network—even putting up a 15-storey warning sign at Chalk Farm, where the staircase has merely 54 steps. As Geoff puts it: “TfL if you're watching please don't ever change your posters! they make me laugh, do more!”
## Mentioned
Geoff Marshall, London Underground, Transport for London, Piccadilly line, Northern line, Covent Garden tube station, Russell Square tube station, Hampstead tube station, Green Park tube station, Tufnell Park tube station, Leicester Square tube station, Chalk Farm tube station, Leslie Green, Tubespotting, Joakim Karud
## Video description
A mention in the Tufnell Park video that I made last week caused some confusion ... how could 110 steps be the equivalent to a 15 storey building?
Ah! Yes, so I went out to explain a running gag that we have, involving London Underground stations and the signs that they have at siaircase which may not be entirely accurate ...
Music by Joakim Karud http://youtube.com/joakimkarud
Geoff Marshall investigates London Underground signage that labels staircases of vastly different depths as the equivalent of a 15-storey building, demonstrating through on-site measurements and mathematical analysis that Transport for London applies the metric arbitrarily.
The Origin of the Fifteen-Storey Discrepancy (0:01)
The investigation began after viewers questioned a caption in Marshall's previous video at Tufnell Park, which claimed climbing its 110 steps was equivalent to ascending a 15-storey building. Marshall explained that the caption referenced an established London Underground notice found at Covent Garden station, a 1906 Leslie Green design where emergency spiral staircase signage warns passengers of a 193-step climb equivalent to 15 storeys.
To test the physical reality behind the sign, Marshall measured the staircase at Covent Garden, finding each step riser to be exactly 17 centimetres. In standard architectural terms, an average building floor measures approximately 10 feet or 304 centimetres, providing an objective benchmark to evaluate London Underground's posted claims.
Identical Warnings Across Disparate Station Depths (4:28)
Marshall expanded his survey to other stations to determine whether signage adjusted for actual step counts. At Russell Square, another Leslie Green station, the spiral staircase comprises 175 steps with identical 17-centimetre risers, yet station posters still define the climb as a 15-storey building.
The inconsistency peaked at Hampstead, the deepest underground staircase on the entire network, featuring 320 steps. Despite also having 17-centimetre risers and requiring nearly double the physical ascent of Russell Square, Hampstead's warning signs present the exact same 15-storey claim, proving that TfL applies the identical label regardless of physical depth.
Mathematical Modeling of Real Versus Stated Heights (8:06)
Marshall evaluated the stations using two mathematical models. In the first model, treating Covent Garden's 193 steps as the intended control yields a baseline of 12.8 steps per floor (193 divided by 15). Applying this baseline to Russell Square's 175 steps results in approximately 13.6 storeys (rounded to 13), while Hampstead's 320 steps divide evenly into exactly 25 storeys.
In the second model, Marshall applied standard architectural dimensions by multiplying each station's step count by the 17-centimetre riser height and dividing by 304 centimetres. This calculation shows Covent Garden equals roughly 10.7 storeys (~11 floors), Russell Square equals 9.7 storeys (~10 floors), and Hampstead equals 17.8 storeys (~18 floors), confirming that none of the three stations actually correspond to a 15-storey building.
Marshall incorporates these calculations into his stand-up comedy show, affectionately urging London Underground not to correct the erroneous posters because the absurdity is entertaining, while jokingly proposing they expand the 15-storey label to stations like Chalk Farm, which has only 54 steps.
## Background
该视频由交通博主 Geoff Marshall 于 2018 年 1 月 16 日发布在 YouTube 频道。视频源于他此前在塔夫内尔公园站（Tufnell Park）视频中提及的“110 级台阶相当于 15 层楼”引发了观众疑惑，因此他决定专门制作一期视频，探寻并解释伦敦地铁各站楼梯标牌上关于“15 层楼”这一长年存在的内部笑梗。
## TL;DR
Geoff Marshall 实地走访了科文特花园站（Covent Garden）、罗素广场站（Russell Square）以及拥有全网最深螺旋楼梯的汉普斯特德站（Hampstead），现场清点台阶数并用卷尺实测出各站踏步均为 17 厘米。他发现无论车站是 175 级、193 级还是高达 320 级台阶，伦敦交通局（TfL）的官方告示牌都一律宣称其“相当于 15 层楼高的建筑”。回到家中后，Geoff 运用相对基准换算与建筑标准层高（304 厘米）两套数学逻辑进行严谨验算，证明没有一个车站真正符合 15 层楼的说法，并幽默地呼吁伦敦交通局千万不要撤下这些荒谬可笑的趣味标牌。
## Atmosphere & style
整个视频洋溢着英式幽默特有的轻松与调侃，兼具硬核交通迷的严谨与脱口秀式的戏剧张力。Geoff 顶着楼梯井的阵阵强风，手持卷尺一本正经地在各个老车站里实地丈量台阶，这种将琐碎日常冷知识提升至“严肃科学调查”的反差感令人忍俊不禁。镜头从实地探访的奔波平稳过渡到深夜伏案算账的解密高潮，让观众在会心一笑中彻底领略到伦敦地铁文化的独特趣味。
## Bulletin
- [05:53](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=353s) 伦敦交通局（TfL）在多个地铁站螺旋楼梯口标注的“相当于15层楼”实为模板化套用，台阶数相差巨大的车站均被标为相同高度。
- [02:43](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=163s) 经卷尺实测，科文特花园站、罗素广场站和汉普斯特德站的单级台阶踏步高度均为标准的17厘米。
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) 按建筑学标准层高（10英尺/304厘米）核算，各站真实层高为10至18层不等，无一站符合标牌宣称的15层楼。
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) 全网最深的汉普斯特德站拥有320级台阶，若以科文特花园标牌为基准折算相当于25层楼，按实际物理高度换算约为18层楼。
## Key takeaways
- [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) Geoff 此行旨在澄清此前视频中提及塔夫内尔公园站约110级台阶相当于15层楼所引发的观众疑惑与背景梗。
- [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) 科文特花园站是该“15层楼”传说的始祖，站内明确设有两处标牌宣称其193级台阶相当于15层高的建筑。
- [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) 科文特花园站与罗素广场站均为1906年莱斯利·格林设计的经典车站，其螺旋楼梯规范上仅限紧急状况使用。
- [02:43](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=163s) 现场卷尺测量证实，科文特花园站与罗素广场站的单级台阶高度完全一致，均为17厘米。
- [02:43](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=163s) 罗素广场站仅有175级台阶，但无论是历史照片还是楼梯口现存标牌，均同样标称为相当于15层楼。
- [05:53](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=353s) 拥有全网最深螺旋楼梯的汉普斯特德站共有320级台阶，台阶高度同样为17厘米，入口标牌却依然写着相当于15层楼。
- [05:53](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=353s) 台阶数量从175级、193级横跨到320级，伦敦交通局却一律使用“15层楼”标牌，构成了地铁迷熟知的荒谬笑梗。
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) 第一种数学计算以科文特花园标牌为基准（每层12.8级台阶），得出罗素广场站约为13层，而汉普斯特德站恰好为整整25层。
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) 第二种数学计算按10英尺（304厘米）建筑层高核算，科文特花园站实际为10.7层（约11层），罗素广场站为9.7层（约10层）。
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) 汉普斯特德站总垂直高度为5,440厘米，实际物理层高为17.8层（约18层），证明没有任何车站真实对应15层楼。
- [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) Geoff 幽默呼吁伦敦交通局千万不要撤换这些搞笑标牌，甚至建议在仅有54级台阶的车站也贴上15层楼的标签。
## Detailed walkthrough
### [00:01](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=1s) 缘起：塔夫内尔公园站引发的“15层楼”疑惑与科文特花园之行
Geoff Marshall 现身格林公园站（Green Park），准备搭乘皮卡迪利线（Piccadilly Line）。他直言自己这次出门是为了做一番解释。前几天他在塔夫内尔公园站（Tufnell Park）拍摄视频时爬了楼梯，并在画面上打出字幕称这相当于爬了一座 15 层高的建筑。评论区不少观众立刻指出 110 级台阶无论如何也算不上 15 层楼。Geoff 承认这是自己的疏忽，当时没有向观众解释这背后的“梗”，因此他决定前往这个笑话的发源地——伦敦地铁“15 层楼”传说的始祖：科文特花园站（Covent Garden）。
```mermaid
flowchart LR
accTitle: London Underground Mystery Tour
accDescr: Geoff Marshall visits three Tube stations to investigate misleading 15-storey staircase signs.
subgraph PiccadillyLine["皮卡迪利线 (Piccadilly Line)"]
CG["科文特花园站<br/>193 级台阶"]
RS["罗素广场站<br/>175 级台阶"]
end
subgraph NorthernLine["北线 (Northern Line)"]
HS["汉普斯特德站<br/>320 级台阶 (最深)"]
end
CG --> RS --> HS
```
科文特花园站是典型的 1906 年莱斯利·格林（Leslie Green）风格车站，配备有垂直电梯和仅供紧急情况下使用的螺旋楼梯。走入车站楼梯口，显眼的标牌明确写着：这里的 193 级台阶相当于 15 层楼高；另一处带有“前往乘车区”（To The Trains）字样的精美指示牌同样写着“攀爬 193 级台阶相当于一座 15 层高的建筑”。Geoff 决定亲自走完这 193 级台阶，并在攀爬过程中探究其中的奥秘。
- 塔夫内尔公园站的楼梯仅有约 110 级台阶，因字幕标注“相当于 15 层楼”而引起评论区观众质疑。
- 科文特花园站是经典的 1906 年莱斯利·格林设计车站，其螺旋楼梯在规范上仅限紧急状况使用。
- 站内明确设有两处标牌，均宣称 193 级台阶相当于 15 层楼高。
---
### [02:43](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=163s) 楼层词源逸事与罗素广场站的实测
走完科文特花园站的 193 级台阶后，Geoff 聊起了一个关于“楼层”（storey/story）英文词源的传说：据说古时某些建筑在每个楼梯平台都会写上一则故事（story/storis），行人每爬一层就能读到一个故事，久而久之层数就演变成了“storey”，不过他承认这可能只是个都市传说。Geoff 确认科文特花园确实有 193 级台阶，同时他特意带了卷尺实测，得出这里的单级台阶高度为 17 厘米。按照常规建筑学标准，一层楼通常约为 10 英尺高，换算为公制单位即 304 厘米（约 3.04 米）。
为了进一步验证，Geoff 前往皮卡迪利线上的另一站——罗素广场站（Russell Square）。该站同样由莱斯利·格林设计，保留着标志性的瓷砖与半圆拱门，顶层上方甚至还看得到当年预留给未来加盖楼层的结构空间。这里的螺旋楼梯共有 175 级台阶，Geoff 掏出卷尺测量，台阶高度同样是 17 厘米。尽管站内部分旧指示牌已被更换，但 Geoff 展示的历史照片证实，这里曾经也挂着告示，声称这 175 级台阶“相当于一座 15 层高的建筑”。不仅如此，当他走下楼梯再次确认时，发现楼梯顶端其实依然留有一块指示牌写着“175 级台阶相当于 15 层楼”。
- 单级台阶高度测量值：科文特花园站与罗素广场站均为 17 厘米。
- 建筑学常见层高基准：1 层楼 = 10 英尺 = 304 厘米。
- 罗素广场站台阶数为 175 级，但其旧标牌与楼梯口现有标牌同样标称为 15 层楼。
---
### [05:53](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=353s) 终极挑战：全网最深的汉普斯特德站
随后，Geoff 在莱斯特广场站（Leicester Square）换乘北线（Northern Line），前往他口中所有楼梯与楼层标牌里的“终极大BOSS”——汉普斯特德站（Hampstead）。这里拥有伦敦地铁网络中最深的螺旋楼梯，整整有 320 级台阶。然而令人啼笑皆非的是，车站入口处的标牌依然赫然写着：这 320 级台阶“相当于爬一座 15 层高的建筑”。
Geoff 顶着楼梯井里的强风徒步爬完全程，并拿出卷尺实测了汉普斯特德站的台阶深度，结果依然是标准的 17 厘米。科文特花园是 193 级，罗素广场是 175 级，汉普斯特德高达 320 级，却通通被官方标牌定义为“15 层楼”。面对这一荒谬现象，Geoff 说道：““So the joke is, is that TfL clearly, just put up signs saying that all tube station have 15 floors, or 15 storeys, no matter if they're 15 storeys or not.”（所以这里的笑话就在于，伦敦交通局显然就是在乱挂牌子，不管是不是 15 层，全都写着每个地铁站都有 15 层楼高。）”
- 汉普斯特德站是伦敦地铁网络中最深的车站楼梯，共有 320 级台阶。
- 经现场测量，汉普斯特德站的单级台阶踏步高度同样为 17 厘米。
- 从 175 级、193 级到 320 级台阶，伦敦交通局（TfL）的标牌一律声称相当于 15 层楼。
---
### [08:06](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=486s) 算账时刻：两种数学计算拆穿“15层”神话
夜幕降临，Geoff 回到家中用纸笔进行数学演算。这个“全伦敦地铁站一律 15 层”的笑话本身也是他地铁脱口秀表演《Tubespotting》中的固定桥段。他通过两种截然不同的数学逻辑进行了拆解：
```mermaid
flowchart TD
accTitle: Two Calculation Methods
accDescr: Flowchart comparing the TfL relative ratio method against actual architectural measurements.
subgraph Method1["方法一：以科文特花园为基准对照"]
M1A["科文特花园 193 级 ÷ 15 层 = 12.8 级/层"]
M1A --> M1B["罗素广场 (175 级 ÷ 12.8) ≈ 13.6 -> 约 13 层"]
M1A --> M1C["汉普斯特德 (320 级 ÷ 12.8) = 整整 25 层"]
end
subgraph Method2["方法二：建筑层高绝对换算 (17cm/级 ÷ 304cm/层)"]
M2A["科文特花园: 193 × 17 = 3281 cm ÷ 304 ≈ 10.7 (约 11 层)"]
M2B["罗素广场: 175 × 17 = 2975 cm ÷ 304 ≈ 9.7 (约 10 层)"]
M2C["汉普斯特德: 320 × 17 = 5440 cm ÷ 304 ≈ 17.8 (约 18 层)"]
end
```
第一种方法假定科文特花园站标牌为真，将其作为“实验对照组”：
193 级台阶除以 15 层，得出平均每层应有 12.8 级台阶。按此比例折算：
- 罗素广场站：175 ÷ 12.8 ≈ 13.6 层（向下取整约为 13 层）。
- 汉普斯特德站：320 ÷ 12.8 竟然不偏不倚刚好等于整整 25 层（毫无余数）。
第二种方法按照真实的物理尺寸与建筑标准进行严格核算：
单级台阶高 17 厘米，标准层高按 10 英尺（304 厘米）计：
- 科文特花园站：193 级 × 17 厘米 = 3,281 厘米。除以 304 厘米，得出其实际高度仅为 10.7 层（四舍五入约为 11 层）。
- 罗素广场站：175 级 × 17 厘米 = 2,975 厘米。除以 304 厘米，得出其实际高度为 9.7 层（四舍五入约为 10 层）。
- 汉普斯特德站：320 级 × 17 厘米 = 5,440 厘米。除以 304 厘米，得出其实际高度为 17.8 层（四舍五入约为 18 层）。
| 车站名称 | 台阶数量 | 标牌声称层高 | 基准换算法 (12.8级/层) | 建筑物理实测算法 (17cm/级, 304cm/层) |
|:--- |:--- |:--- |:--- |:--- |
| **罗素广场站 (Russell Square)** | 175 级 | 15 层 | 约 13.6 层（约 13 层） | 2,975 cm ÷ 304 cm ≈ **9.7 层（约 10 层）** |
| **科文特花园站 (Covent Garden)** | 193 级 | 15 层 | 15 层（基准） | 3,281 cm ÷ 304 cm ≈ **10.7 层（约 11 层）** |
| **汉普斯特德站 (Hampstead)** | 320 级 | 15 层 | **整整 25 层** | 5,440 cm ÷ 304 cm ≈ **17.8 层（约 18 层）** |
通过实际测量计算可知，没有任何一个车站真的是 15 层楼高。Geoff 在视频最后幽默地向官方喊话：““TfL if you're watching, please don't ever change your posters! they make me laugh, do more!”（伦敦交通局如果你们在看这个视频，请千万别把海报改掉！它们太搞笑了，多弄点这种标牌吧！）”他甚至建议伦敦交通局干脆去只有 54 级台阶的乔克农场站（Chalk Farm）也立一块牌子，宣布那里同样相当于 15 层楼，让“所有伦敦地铁站永远都是地下 15 层”彻底变成一个全民共享的经典笑梗。
## Notable quotes
> [05:53](https://www.youtube.com/watch?v=pBTvmrRGlbE&t=353s) So the joke is, is that TfL clearly, just put up signs saying that all tube station have 15 floors, or 15 storeys, no matter if they're 15 storeys or not. — Geoff Marshall
## Mentioned
Geoff Marshall, 伦敦交通局 (TfL), 科文特花园站 (Covent Garden), 罗素广场站 (Russell Square), 汉普斯特德站 (Hampstead), 塔夫内尔公园站 (Tufnell Park), 格林公园站 (Green Park), 莱斯特广场站 (Leicester Square), 乔克农场站 (Chalk Farm), 皮卡迪利线 (Piccadilly Line), 北线 (Northern Line), 莱斯利·格林 (Leslie Green), 《Tubespotting》, Joakim Karud
## Video description
A mention in the Tufnell Park video that I made last week caused some confusion ... how could 110 steps be the equivalent to a 15 storey building?
Ah! Yes, so I went out to explain a running gag that we have, involving London Underground stations and the signs that they have at siaircase which may not be entirely accurate ...
Music by Joakim Karud http://youtube.com/joakimkarud
[Source](https://www.youtube.com/watch?v=pBTvmrRGlbE)
Source quotes
[5:53] Geoff Marshall: So the joke is, is that TfL clearly, just put up signs saying that all tube station have 15 floors, or 15 storeys, no matter if they're 15 storeys or not.
Original transcript
[0:01] (upbeat music)
[0:17] I'm at Green Park
[0:23] Gonna jump on the Piccadilly Line
[0:25] Got some explaning to do ...
[0:28] look at that bright sun, is that making me a halo? I suspect so, let's get down below
[0:41] So here's the deal, other day i made
[0:43] a video where i was at Tufnell Park, and I climbed up the staircase
[0:45] and i put a caption on saying it was the equivalent
of a fifteen-storey building
[0:57] Some of you - quite rightly - in the comments, said
[1:00] that's not a fifteen storey building!
[1:04] and it's kinda my fault for not explaining the joke, so ...
[1:07] i need to explain the joke
[1:10] but i also need to go to the source of that joke,
the original
[1:12] fifteen-storey building
[1:14] which is Covent Garden!
[1:35] So, Covent Garden is classic case
[1:39] of a 1906 Leslie Green station which has lifts
[1:41] and a spiral staircase, and technically
[1:45] the spiral staircase, is only meant to be used in an emergency
[1:50] Now this, this is the spiral staircase
[1:52] and there is quite a clearly, a sign that says
that the 193 steps
[1:56] is equivalent ... to 15 floors
[2:00] it's here again
[2:02] with a really nice 'To The Trains' sign
[2:04] there are 193 steps to climb
[2:07] the equivalent, to a fifteen storey building
[2:11] again - this station, is fifteen floors below ground
[2:15] i'm gonna walk ... 193 steps
[2:19] and we'll talk about my theory at the top
[2:43] So, Covent Garden
[2:45] 193 steps
[2:47] claims to be a fifteen storey,
or fifteen floor building
[2:50] by the way there's a story ... as to why it's called storey
[2:54] apparantly, historically in some places
[2:56] that had steps, they used to put stories
S - T - O - R - I - S
[3:00] on every floor!
[3:02] which then became every story, so that as people climbed the steps
[3:06] they could read stories,
[3:09] that might be an Urban Legend!
[3:11] 193 steps at Covent Garden, that bit is correct
[3:13] i've counted it, don't get me started on
[3:15] London Underground stations which have incorrect signage
for how many steps they have
[3:19] save that for another video
[3:21] So on the way up ... i also
[3:23] i brought my tape measure
[3:27] obviously, why wouldn't you bring your tape measure
[3:29] and i measured some of the steps here, at Covent Garden
they're seventeen centimetres
[3:32] err, you can see where this is going can't you?
this is going to be a maths thing
[3:37] now if you google around online,
[3:40] look at architects websites
[3:42] they tell you that a storey - or one floor
[3:43] is typically 10 feet
[3:45] imperial measurments - scrap that
we'll do the maths, that is three hundred and four
[3:49] just over three metres,
304 centimetres
[3:52] per floor / storey
[3:54] we'll do the maths completely
once i've taken you to somewhere else
[3:59] on the network, this way!
[4:28] so we're at Russell Square
[4:29] where ther's 175 steps
[4:32] let's do these
[4:34] So i'm walking up ... 175 steps
[4:39] of Russell Square, where again i've measured
[4:42] and the depth of the step, is 17cm
[4:56] Ok, Russell Square, it's a great Leslie Green station by the way
[5:00] amongst all the tiles, and the nice
[5:02] semi circular arches there, note how the top floor, look
[5:05] they always used to leave space
[5:07] on top of the building for them to be built on, but here at Russell Square
[5:10] is one that they never built on, a little get there from my
[5:13] knowledge .. tube bank of Underground history
[5:17] what a great white van blocking the shot!
[5:19] the point is, i measured the steps again
[5:23] they're 17cm, there's 175 of them here at Russell Square
[5:26] now - it doesn't say it anymore
[5:29] but i have photographic evidence, here is the photo on screen now
[5:30] it was so long ago that there used to be a sign here, also saying
[5:35] that those 175 stairs, were the equivalent
[5:40] of a fifteen storey building
[5:41] so Covent Gardem 193 stairs, saying its fifteen storeys
[5:44] Russell Square, 175 stairs, also saying its fifteen storeys
[5:49] we've got one more example
[5:51] i need to take you to!
[5:53] So i'm changing ... at Leciester Square, from the Piccadilly Line
[5:57] to the Northern Line, that's handy, the train has just pulled in
i'll take that, lovely!
[6:28] so here's the fun thing, as i actually went
[6:30] back onto the Tube at Russell Square
[6:34] and i went down the spiral staircase, i got a shot on my phone
[6:36] there is still a sign up
[6:39] at the top of the stairs, saying ...
[6:41] 175 steps, IS equivalent to a fifteen floor building
[6:45] so the sign is still there, but there's one more place here
[6:48] in a few more stops on the Northern Line
[6:51] which is like, the Daddy ... of all steps, and floor signage
[7:14] Ok, this it it! Hampstead.
[7:17] this is the deepest - ooh windy
[7:20] this is the deepest staircase on the network
[7:23] 320 steps, and yes, there's the sign
[7:25] saying it's the equivalent of climbing a fifteen-storey building
[7:33] Let's do it!
[7:48] Ok, Hampstead tube ... 320 steps
[7:51] still says, it's the equivalent of fifteen floors
[7:54] i measure the steps, again they're 17cm
[7:57] something very wrong, is going on here
so it's time to do some maths
[8:06] Ok, so i've come home
[8:08] that is wow, that's is a really, sorry i'm just
[8:11] that is a really yellow screen
[8:14] where are my scissors?
[8:16] it's dark, i couldn't find a cafe to sit in
[8:19] i've come home this avening i just thought i'd do the maths part
[8:21] when i got back here home this evening
[8:23] except it's now dark outside, i can't wait for summer to be here
[8:25] light will come in the window, and then it won't look so yellow
[8:29] and basically
[8:31] i just need to so some quick maths
[8:34] to demonstrate what's going on
[8:36] so the joke is, is that TfL
[8:39] clealy, just put up signs
[8:41] saying that all
[8:44] tube station have 15 floors, or 15 storeys
[8:47] no matter if they're 15 storeys or not
[8:49] and i incoiporate that into my stand up comedy show
[8:52] about the Tube, called "Tubespotting"
[8:55] this to me is like, because Covent Garden is so infamous
[8:58] the standard marker
[8:59] the deepest tube station on the network, which is Hampstead
[9:02] 320 steps ... how many floors is that?
[9:06] is also fifteen, see!
[9:10] and i'm like .. hang on a second, you just said TfL that
[9:13] that's like what, how can that also be fifteen?
[9:16] they probably just made a mistake
[9:20] it's ... which is interesting because i got out at Russell Square the other day
[9:27] and so the gag is
[9:29] that TfL just say "we'll put 15 floors" no matter how many steps it has
[9:34] that's the gag!
[9:35] but what i wanted to do
[9:37] i wanted to do the actual, actual maths
[9:40] so there's two quick things to do here
[9:42] so we'll do, errr Covent Garden
[9:47] Russell Square ...
[9:50] aaaaaand Hampstead
[9:52] so these are our three stations
[9:55] that will do, now, so what we know
[9:57] is that Covent Garden, is 193 steps
[10:01] Russell Square is 175
[10:03] and Hamstead is 320,
now if you divide ...
[10:05] if you take Covent Garden
as like, the marker because i remember seeing
[10:09] to me Covent Garden has always been the base
[10:13] what's the word? where you take somethiing as like
[10:16] the control! that's the word i'm thinking of
[10:18] that's our control in this experiment
[10:21] we're gonna take Covent Garden as read, let's say
there really is fifteen floors
[10:24] which it isn't - which we'll get to in a minute
[10:26] but that would be 193 divided by 15
[10:29] gives you 12.8, so if you then divide
[10:32] if you divide the 175 at Russell Square
[10:35] by 12.8 you get, actually 13, 13.6 but we'll round it down
[10:42] so Russell Square measurement, should be really
thirteen floors, and then
[10:48] bizarrely Hampstead, if you divide
[10:51] 320 by 12.8
[10:53] if there are Maths people out there, you will love this
[10:55] it is a perfect 25! no remainder .. so divided by 12.8, equals ...
[10:58] so there, i've done those in pink, you can't see that can you?
[11:06] when i do the next batch in a second, i won't do it in pink
[11:08] it's 15! err, 13 ...
[11:11] and 25
[11:13] however! as mentioned earlier ...
[11:15] i'll do it in Green this time, so again
[11:18] this time, as i think i mentioned earlier in the video
[11:22] architect design, say that a storey is 10 feet
[11:25] 12 inches in a foot, i think it's 30 point ... 4 centimetres
[11:30] in 12 inches / 1 foot, that means that one floor
[11:34] three hundred and four .. f ... f, what? four!
[11:38] centimetres. is that right? yes!
[11:42] i think that's right. my maths works out, trust me.
[11:45] if you then .. and do, it's imporant and that's why i measured it
[11:48] for 17, if you do 17
[11:51] centimetres, which is the depth of a step
[11:53] by 193 at Covent Garden
[11:55] i hope this is right, because you'll so tell me if this is wrong
[11:58] 3,281 centimetres, divide that by 304, so actually ...
[12:01] Covent Garden, is 10.7!
[12:07] floors .. high. you could round that up to 11.
[12:11] if maths is wrong, tell me in the comments. that's fine.
[12:15] applying the same maths
[12:17] 17! centimetres ...
[12:20] times the 175 steps at Russell Square
[12:24] i think comes out at 2,975 centimetres, dived by 304, gives you ...
[12:27] 9.7! which we'll round up to 10
[12:33] so Russell Square is really just under ten
[12:36] floors, storeys, and 10 storey building
[12:39] and then finally, we have to Hampstead ...
[12:42] 17cm times 320
[12:44] comes to ...
[12:47] 5,440 centimetres, which is, divided by 304
[12:49] a grand total of ...
[12:53] 17.8 which i'll round up to 18
[12:56] it's an 18 floor .. storey, building, that is my maths!
[13:00] if you think i've done it wrong! i'm sure you'll tell me
[13:05] TfL if you're watching
[13:07] please don't ever change your posters! they make me laugh, do more!
[13:10] go to Chalk Farm where there's only 54 steps
[13:14] and put up a sign there, saying
[13:15] this is equivalent of 15 storey building
[13:17] let's make this a running gag! all tube stations ...
[13:20] forevermore, should always
[13:22] be 15 .. (laughs) floors, deep underground
[13:26] right?
[13:28] thanks!
[13:29] (upbeat music)
