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The assembly line – which began in the slaughterhouse, not the car factory

The assembly line was not invented in the car industry. It came from the Chicago slaughterhouses, where animals were taken apart on rails. Here is how the idea was reversed, what happened to the price – and what it cost the people standing at the line.

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What this covers

Where the idea actually came from
The slaughter line, reversed
How cars were built before
What Ford really invented
Highland Park, and the numbers
The price that fell
What it cost the people

What this covers (cont.)

What the line does to work

The line that ran the other way

In the slaughterhouses of Chicago and Cincinnati in the late nineteenth century, carcasses hung from overhead rails. A trolley carried them from worker to worker, and each person made one particular cut before the carcass moved on.

It was not an assembly line. It was a disassembly line.

What moved: the workpiece, not the worker.
What stayed put: the human being, with one cut and one tool.
What Ford saw: that the direction did not matter. If you could take something apart this way, you could put something together in exactly the same way.

How cars were built before

To see how large this was, you need to know how a car actually came into being before 1913. And it was not mass production in any sense.

Two ways to make a door fit

Craft

The part is fitted to the car

The door is worked until it fits this particular frame
Every car ends up slightly different from the last
The deviations accumulate through the car
A door from one car does not fit another
Requires a skilled fitter at every joint

Mass production

The part is the same every time

The door is made within a tolerance
Every frame is within the same tolerance
No adjustment needed
Any door fits any car
Requires gauges, not craftsmen

The left-hand column is why cars were expensive. Not because materials cost much, but because every single joint needed a skilled person spending time making two parts meet. And note the fourth point: when every car is unique, there are no spare parts either – only blanks that have to be fitted all over again.

What Ford really invented

Here is the nuance that usually drops out: Ford did not invent interchangeable parts. He did not invent gauging, and he did not invent machines able to cut hardened metal.

The order that made it possible

First: precise partsParts must fit without adjustment. This came in 1908, five years before the line.
Then: fixed division of labourEach worker performs one operation, in one place, every time.
Then: move the workpieceThe car is carried past the workers instead of the workers walking to the car.

The order is not incidental, and it is the most important lesson for anyone wanting to copy the model. The assembly line is the last step, not the first. Introduce the line before the parts fit and you have automated nothing – you have merely made it impossible for people to take the time to fix what does not fit.

Highland Park

Ford's first moving line was installed at Highland Park in early 1913, and it was not for the whole car – it was for flywheel magnetos. From there the principle spread through the factory.

Before and after, in numbers

Measure	Before	After
Time per chassis	Around 12.5 hours	93 minutes
Rate in 1914	—	A Model T every 24 seconds
Production 1914	—	Over 202,000 cars

Eight times faster in a single year, without any new machine doing the actual work. What changed was the order and the motion. That is why this is organisational history as much as technological history.

The price

The consequence for the customer is the part people remember, and it is dramatic.

Model T, price over time

1908$850

1914$490

1924$260

ExpensiveCheap

Between 1908 and 1927 more than 15 million Model Ts were built. The point is not that the car got cheaper – it is that it changed market. It went from something the wealthy bought to something the people building it could buy. That is the social change the assembly line actually set off.

What it cost

Here comes the part that rarely appears in the edifying version of the story, and it is necessary to understand the rest.

The five dollar day was not generosity. It was the price of getting people to stay.

What applied before: $2.34 for a nine-hour day.
What came in January 1914: five dollars for an eight-hour day.
What it bought: that people were willing to submit to the pace and discipline of the line.
Why it is worth saying plainly: the pace did not get gentler. The compensation got higher. Those are two entirely different things, and the difference is the whole point.

What the line does to work

Finally, the part worth carrying forward, and it applies far beyond car factories.

Who sets the pace

Without a line

The worker

You decide when to take the next part
You can spend extra time on something difficult
You can catch up later
Variation in pace is invisible from outside

With a line

The line

The next unit arrives regardless
If you fall behind, everyone sees it
You cannot catch up – only stop everything
The pace is a setting, not a negotiation

This is what makes the assembly line something other than an efficiency measure. It moves control over the pace of work from the person doing it to the person setting the line. The whole history of working life after 1913 can be read as an argument about that transfer – and the argument continues in the next episode, on Taylor and Toyota.

What is worth taking with you

That the assembly line came from the slaughterhouses, and that it originally ran the other way.

Key points

The idea came from the Chicago slaughterhouses, where animals hung on rails and were taken apart – not put together.
Ford reversed the disassembly line into an assembly line.
Before this, parts were filed and worked by hand until they fitted, and every car was unique.
What Ford achieved first was parts precise enough that they needed no hand-finishing.

Key points (cont.)

A chassis went from around 12.5 hours to 93 minutes.
In 1914 a Model T came off the line every 24 seconds.
The price fell from $850 in 1908 to $260 in 1924.
Turnover was 380 per cent in 1913. The five dollar day came in January 1914.

Questions this answers

Who invented the assembly line?
What does pig slaughter have to do with building cars?
How were cars built before the assembly line?
Why did doors have to be fitted by hand?
How much faster did production get?
Why did Ford introduce the five dollar day?

Questions this answers (cont.)

What is actually new about an assembly line?

Sources

The Henry Ford – Assembly Line (research guide)
Library of Congress – Ford Implements the Moving Assembly Line
The Henry Ford – Crowd of Applicants outside Highland Park Plant after Five Dollar Day Announcement, January 1914
James P. Womack, Daniel T. Jones and Daniel Roos – The Machine That Changed the World (1990)

Spørretimen

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www.sporretimen.no/en/episodes/ford-samlebandet/