Fixing the Portobello Police Station Clock

修理波托贝洛警察局的时钟

Written on 11th April 2026 I got a message from a friend today which read along the lines of “I know we were going to meet in Edinburgh today, but do you fancy meeting in Portobello instead and trying to fix the clock in the old police station with me?” I don’t know about you, but clambering around the dusty nineteenth century clock tower of an abandoned police station sounds an ideal way to spend a Saturday afternoon to me, so I jumped at the chance. 写于2026年4月11日。今天我收到一位朋友的消息，大意是：“我知道我们原定今天在爱丁堡见面，但你有没有兴趣改在波托贝洛（Portobello）见面，和我一起尝试修理旧警察局的时钟？”我不知道你怎么想，但对我来说，在废弃警察局那布满灰尘的19世纪钟楼里攀爬，听起来是度过周六下午的理想方式，所以我毫不犹豫地答应了。

The rather grand Portobello Police Station building. This was in response to a message from Action Porty: “Can you help keep Portobello on time? Action Porty has recently bought the Police Station for the community, but we can’t work out how to change the time on the clock tower! We wondered if there was anyone in the community with expertise that could advise us of the details for changing the time? Or who best to contact for help?” 波托贝洛警察局大楼相当宏伟。这是为了回应“Action Porty”组织的一条消息：“你能帮忙让波托贝洛的时钟保持准时吗？Action Porty 最近为社区买下了这座警察局，但我们搞不清楚如何调整钟楼的时间！我们想知道社区里是否有具备专业知识的人能指导我们调整时间的细节？或者建议我们联系谁寻求帮助？”

The bit I hadn’t figured out was that clocks are high up. If we were to fix the clock we would be next to it and so we would also be high up. And being high up involves heights, and steep long ladders are needed to get up high. I suppressed my whimpers at climbing up the rather high, steep ladder into the likely spider-infested darkness and was rewarded with an explore of the attic, which lead to another set of steps which went to the clock tower itself. Once there we were rewarded with the magnificent sight of the clock mechanism and its three clock faces. 我没预料到的是，时钟安装在高处。如果要修理时钟，我们就必须靠近它，这意味着我们也得在高处。在高处就涉及高度问题，而且需要爬很长很陡的梯子才能上去。我强忍着对攀爬那又高又陡、可能布满蜘蛛的黑暗梯子的恐惧，最终得以探索阁楼，并顺着另一组台阶来到了钟楼内部。到达那里后，我们看到了壮观的时钟机械结构及其三个表盘。

Construction of the building apparently started in 1877 and it seems quite feasible that this was an original mechanism. Modifications had been made - electric motors powered the mechanism and a control box allowed the clock chime to be turned off overnight. The building was built to house meeting, administration and courts for Portobello burgh council. After Portobello was absorbed into Edinburgh the building became a library, and then a police station. The Scottish Land Fund has since enabled it to be purchased for community ownership and when I went there many volunteers were removing the 1970s polystyrene ceiling tiles and wood-chip wallpaper to reveal the original grandeur of the building. 这座建筑显然始建于1877年，这套机械装置很可能就是原装的。后来进行过一些改造——电动机驱动了机械装置，一个控制盒可以关闭夜间的报时功能。这座建筑最初是为波托贝洛自治市议会提供会议、行政和法院办公场所而建的。波托贝洛被并入爱丁堡后，这里先是变成了图书馆，后来又成了警察局。苏格兰土地基金（Scottish Land Fund）此后资助社区买下了它。我去的时候，许多志愿者正在拆除20世纪70年代的聚苯乙烯天花板瓷砖和木屑壁纸，以重现建筑最初的宏伟风貌。

Setting the clock

调整时钟

The first step was to figure out how to set the time. This is probably easy to someone in the know, but we weren’t. We figured that the clock is driven from the small motor, through a series of gears onto a shaft which rotates once per hour. This shaft is split into three - one for each face, and drives the minute hand directly. A gear on each clock face derives the hour hand. If we could disconnect the motor maybe we could turn the shaft directly and set the time. Sure enough - we found a pawl on one of the gears which could be lifted out of the way. Once this was done the shaft turned easily and we could set the time. 第一步是弄清楚如何设置时间。对于内行来说这可能很简单，但我们不是。我们推断时钟是由小型电机驱动，通过一系列齿轮传动到一个每小时旋转一圈的轴上。这个轴分为三段——每个表盘一段，直接驱动分针。每个表盘上的齿轮则驱动时针。如果我们能断开电机，也许就能直接转动轴来设置时间。果然，我们在其中一个齿轮上发现了一个可以抬起的棘爪。一旦棘爪被移开，轴就能轻松转动，我们便可以设置时间了。

Each hand had a counterweight on the clock face and we could set the time by imagining the hand we couldn’t see opposite to each counterweight. We had a slightly stupid moment when we thought we’d got it wrong, and the clock was running backwards - only to realise we were inside the clock and so were looking at it the wrong way. Doh. We had to head down to the ground to check that the time was correct - but - phew - time was OK and not running backwards. 每个指针在表盘背面都有一个配重，我们可以通过想象指针在配重的对面来设置时间。我们经历了一个有点蠢的时刻：我们以为自己弄错了，时钟在倒着走——后来才意识到我们是在时钟内部，所以看反了。哎呀。我们不得不下到地面去确认时间是否正确——呼——还好，时间是对的，并没有倒着走。

Setting the chime

调整报时

Figuring out the chime was more difficult. The original mechanism had been modified, and switches and a motor had been added. These led to a box containing a circuit board which definitely was not from 1877. It contained a PIC 16F628 microcontroller which had a suspected date-code of 2001. There were a number of relays, a power supply and a battery charging circuit to charge the included lead-acid battery. I assume this box would be getting on for 1/4 century old, but it still seemed to work. No idea how good the battery was; maybe this should be tested another time. 弄清楚报时系统要困难得多。原始机械装置经过了改造，增加了开关和电机。这些装置连接到一个包含电路板的盒子上，这显然不是1877年的产物。它包含一个PIC 16F628微控制器，其日期代码疑似为2001年。盒子里还有一些继电器、电源和一个用于给铅蓄电池充电的电路。我估计这个盒子已经快四分之一个世纪了，但它似乎还能工作。不知道电池状况如何；也许下次应该测试一下。

We have no idea who designed and built this box; there were no obvious description markings. Is it a standard thing, or just a one-off for this clock? A mystery unmarked circuit board, ripe for deciphering. This box didn’t have much of a user interface, other than a non-obvious button marked “advance”. The only problem was that pressing it did nothing. How did this thing work? Surely you had to set the time somehow. 我们不知道是谁设计并制造了这个盒子；上面没有明显的标识。它是标准产品，还是专门为这个时钟定制的？这是一个神秘的无标记电路板，等待着被破解。这个盒子几乎没有用户界面，只有一个标记为“advance”（前进）的不起眼的按钮。唯一的问题是，按下它没有任何反应。这东西是怎么工作的？肯定有某种设置时间的方法。

A summary after more head scratching, measuring and fiddling: 经过一番抓耳挠腮、测量和摆弄后的总结：

TLDR: The box switches a mains powered motor (the blue one with the chain in the picture above) which controls the chime striker mechanism. When the motor is powered the clock strikes continuously. A switch on the striker tells the box how many chimes have taken place, so it knows when to stop. A switch on the clock shaft triggers on the hour and tells the box when it should chime. The box controls the clock motor. The “reset” switch appears to do nothing other than switch off the clock motor. (As I write this, I assume it also sets the ‘time’ back to midnight, but this is to be tested). The “advance” button needs to be held for a few seconds before anything happens. When it is released, the clock will chime. When pressed and released again, it will chime again for the next hour. Setting the time appears to be done by pressing advance until the correct hour is reached. The “Status” LED flashes some kind of code - long long, short short short. I assumed the number of flashes would correspond to the time but apparently not. We didn’t have time to figure this out before we had to leave. The box has no “clock” as such in it - it just has a counter which keeps track of the hour. All timing is done from the “hour trigger” switch from the main mechanism. The two switches are connected via banana plugs to the box; the box has cables for the GMT/BST switch, mains input, clock motor out, chime motor out. I had hoped we could do a “test” by letting the clock chime thirteen (or even just strike continuously), but I was up in the tower with a bunch of spoilsports who wouldn’t let me. Oh well, next time when they’re not around. Yay - It tells the… 简而言之：这个盒子控制着一个市电驱动的电机（上图中带链条的蓝色电机），该电机控制报时敲击装置。当电机通电时，时钟会持续敲击。敲击器上的一个开关会告诉盒子已经敲击了多少次，以便它知道何时停止。时钟轴上的一个开关在整点时触发，告诉盒子何时应该报时。盒子控制着时钟电机。“重置”开关似乎除了关闭时钟电机外没有其他作用。（写到这里，我推测它可能还会将“时间”重置为午夜，但这有待测试）。“前进”按钮需要按住几秒钟才会有反应。松开后，时钟会报时。再次按下并松开，它会为下一个小时再次报时。设置时间似乎就是通过按下“前进”直到达到正确的小时数。“状态”LED灯会闪烁某种代码——长、长、短、短、短。我原以为闪烁次数对应时间，但显然不是。我们离开前没时间弄清楚这一点。盒子里本身没有“时钟”——它只有一个记录小时数的计数器。所有的计时都来自主机械装置的“小时触发”开关。这两个开关通过香蕉插头连接到盒子上；盒子上还有用于格林威治标准时间/英国夏令时（GMT/BST）切换、市电输入、时钟电机输出和报时电机输出的电缆。我本希望通过让时钟敲响十三下（甚至只是持续敲击）来进行一次“测试”，但我在塔楼里和一群扫兴的人在一起，他们不让我这么做。好吧，下次等他们不在的时候再说。耶——它报时了……