Picture an unclosed parking line near the edge of the table. One wrong turn later and disaster. The engineer then has to bring back the bricks to the table and let the MOCer to rebuild the train. This is not just theory, but past experience.

To prevent this kind of trouble, a simple answer is to put bumpers on the end lines. Let us have a brief review of what has been done on that subject.

Official bumpers

You will be able to find in some LEGO official sets a bumper, as part of the main model or in an alternative construction. These models are solid enough.

 Set 7745 : bumper is part of alternative building.

 Idea book 7777 : Pay attention, this bumper has been designed for 12V tracks, a modification is needed to fit the 9V tracks.

 Set 4553

 Set 4512 : the bumper is used to close the parking line.

Static bumpers

Like the previous models, the following ones have to take the blow of a running train. Strength is needed.

 Model by Carsten CaL Luetjens

This model especially strongly built.

 Model by Nate Jacobs. Fitted out with a 9V light.

This model has no buffer, the train hits directly the structure.

 Model by the author, like it can be seen in french railways.

Not robust, a decorative accessory.

Dynamic bumpers

Dynamic bumpers are bumpers with shock absorber, allowing them to dissipate a part of the whole impact energy.

Model by blackflame

The model does not resist correctly to a fast train collision and the design is a bit harsch.

 The model by the author, as is seen in a terminus, with absorber buffer.

Motorized bumpers

Model by A&M LWorks

This accessory is not really a bumper but it allows to push back an empty wagon.

Parking lights

If you plan to add a light to your bumper, you have to know about the rules in your country.

In France the rule is
 red light on main lines (terminus) ;
 purple light on parking lines.

In conclusion, there exists a numerous ways to build bumpers with LEGO bricks. Depending on your needs, you can choose an aesthetic but fragile design for a static scene or a massive bumper to stop trains started off at full speed.

In general, a bumper will much more resistant if it has encroachment onto the tracks and, eventually on the baseplate.

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Finally, as a bonus, I propose you this red chequered stop marker with light, which would find his place as a trackside accessory.

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Find all the CAD files in the following zip :

Les fichiers CAD des heurtoirs

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Last minute addition : the Fuel Refinery set 149 propose a bumper for 4,5V tracks.