We have improved the calculation of Horizontal Clash Analysis (starting from MITS 2.4.33.0 and above), which allows users to have a sense of the clashes more realistic as the thickness between utilities are taken into consideration and divided into inner profile and outer profile. Horizontal clash analysis is applied for node to node and node to pipe checking, while pipe to pipe checking is categorized under vertical clash analysis. Vertical clash calculations are still the same, which you may refer to in this blog post; “How Clash Analysis Works”, or if you are using previous versions of MiTS, you may as well refer to the said blog post.
Refer to this blog post for step guidelines; How Clash Analysis Works
“-” clash #
-ve clash is divided into two, which are inner profile clash and outer profile clash.
The inner profile clash is a clash between utilities which involves the inner profile. Examples are shown as below.


The distance of the clash is shown in the Clash Analysis report

The value is measured between the maximum distance of the inner profile of the entities that clashes. For example, Manhole 30 clashes with Drain 12 at ID3, the value stated in the report is -0.234 m. The distance is measured as per image below


The outer profile clash means that the entities are clashed only within the thickness and involving the outer profile of the entities thickness. For example is as image below



The value is measured between the maximum distance of the outer profile of the entities that clashes. For example, Manhole 16 clashes with Drain 38 at ID2, the value stated in the report is -0.047m. The distance is measured as per image below


Bear in mind that, whenever the entities are clashed, either inner or outer profile, the value is “-” distance. Unlike the previous version, the – value is only applied towards the inner profile.
“+” clash #
“+” clash denotes that the gaps between utilities are less than the minimum requirement of the clearance and are not clashing. Minimum horizontal clearance distance can be adjusted in the Parameter Settings.
“Options > Project Parameters > Clash Analysis > Min. Horizontal Clearance (mm)”

Example of the “+” clash is as diagrams below



As above diagrams observed, the utilities are not clashing, however the gap between them is less than the required 600 mm. The measurement is calculated between the minimum distance of the outer profile


The other clash in horizontal is the “-” sign with no value. The sign shows that the entities are overlapped from the above view, but they are not clashing vertically. This clash remains the same as previous, which you may refer to How Clash Analysis Works under section 3.1