CAGE-BEARING 5M3473 - Caterpillar

Why Modifications To ROPS Often Void Their Certification
Every design for a ROPS/FOPS structure has to meet or exceed demanding tests to be certified. The minimum performance criteria for these structures is based on the weight of the machine, and was developed under the sponsorship of the Society of Automotive Engineers (SAE) which has been incorporated into government regulations. The performance criteria require a destructive test of a representative ROPS system which includes the ROPS structure and the machine frame member to which it is attached. The test consists of bending the ROPS laterally until it deflects sufficiently to absorb a specified amount of energy with a minimum specified bending force based on the type of machine and its weight. The deformed ROPS then must withstand a vertical load of at least twice the machine's weight.
Illustration 2. Canopy legs cracked by addition of water containers on the ROPS canopy to fight fires.Every new ROPS/FOPS has a certification plate that lists the SAE and ISO (International Standards Organization) practices that must be complied with to pass the preceding tests. See Illustration 3.
As stated on the plate, structural damage, an overturn, modification, alteration, or incorrect repair can void the certification. Now, you may wonder if the ROPS can ever be used if something happens to it. Yes, the ROPS can be used if the repairs or installation of attachments are within limits specified by the manufacturer. Beyond these limits, no amount of reinforcements will prove or disprove the question of certification. Recertification can not be done by calculations. The only way to prove its capability is to subject the ROPS system to all the tests required by SAE and ISO. Obviously, this is not practical since the ROPS would be destroyed. This simply means that the ROPS may not only be unsafe, but also illegal in some countries.
The previous paragraph mentions that limited repairs or installation of attachments in certain designated areas can be done without voiding the certification. This is covered in detail in the following Special Instruction Forms prepared by Caterpillar Tractor Co.:
English SEHS6929-02French SFHS6929-02German SGHS6929-02Spanish SSHS6929-02These instructions are for use by Caterpillar dealers as a guide for ROPS service without voiding ROPS certification. They cover inspection, permitted repairs, replacement criteria, and permitted modifications and installation of attachments.
Do not make any repairs, modifications, or installation of any attachments to the ROPS/FOPS structure that is not authorized in the applicable Special Instruction. Such action will not only void the certification but will reduce, if not eliminate, the ability of the structure to provide crush protection for the operator in a rollover or from a falling object.
Illustration 3. Example of certification plate attached to all new ROPS/FOPS structures.Users should not make any repairs or modifications to a ROPS/FOPS structure without concurrence of a Caterpillar dealer. Failure to do so may result in a ROPS that is uncertified and must be replaced to comply with the government regulations.
How Caterpillar Certifies ROPS/FOPS Structure Systems
The ROPS/FOPS structure system includes the basic structure, mounting components